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Everyman, I will go with thee, and be thy guide, 
In thy most need to go by thy side. 



This is No. 262 of Everyman's Library. A 
list of authors and their works in this series 
will be found at the end of this volume. The 
publishers will be pleased to send freely to all 
applicants a separate, annotated list of the 









WILLIAM HARVEY, born at Folkestone, 
Kent, in 1578. Educated at Canterbury and 
Cambridge. In 1607 elected fellow of the 
College of Physicians and in 1609 made 
assistant physician at St. Bartholomew's 
Hospital. Died in 16^7. 

G17- .1 




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First Published in this Edition 19OJ 

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However much the renewal of classical learning in 
the fourteenth, fifteenth, and sixteenth centuries may 
have furthered the development of letters and of art, it 
had anything but a favourable influence on the progress 
of science. The interest awakened in the literature of 
Greece and Rome was shown in admiration not only for 
the works of poets, historians, and orators, but also for 
those of physicians, anatomists, and astronomers. In 
consequence scientific investigation was almost wholly 
restricted to the study of the writings of authors like 
Aristotle, Hippocrates, Ptolemy, and Galen, and it 
became the highest ambition to explain and comment 
upon their teachings, almost an impiety to question 
them. Independent inquiry, the direct appeal to 
nature, were thus discouraged, and indeed looked upon 
with the utmost distrust if their results ran counter to 
what was found in the works of Aristotle or Galen. 
This spell of ancient authority was broken by the 
anatomists of the sixteenth century, who determined at 
all costs to examine the human body for themselves, 
and to be guided by what their own observations 
revealed to them ; and it was finally overcome by the 
independent genius of two men working in very different 
scientific spheres, Galileo and Harvey. These illus- 
trious observers were contemporaries during the greater 
part of their lives, and were some years together at the 
famous University of Padua. Galileo and Harvey 
refused to be bound by the teachings of Aristotle and 
Galen, and appealed from these authorities to the 
actual facts of nature which any man could observe for 


viii Editor's Introduction 

himself. Their scientific work is therefore of interest, 
not only for the innate value of the discoveries they 
made, but also because it shows them as pioneers in 
that independent spirit of scientific inquiry to which 
the great advance in natural knowledge since their time 
is so largely due. 

Harvey's work, by which his name has been made 
immortal, strikingly illustrates this. He was the first_ta 
show the nature of the movements of the heart, and 
how the blood moved in the^bjidyT ffe~3Id so~By 
putting on one side authority, and directly appealing to 
observation and experiment. The completeness of the 
success with which this independent line was taken, as 
exemplified in his treatise " On the Movement of the 
Heart and Blood," is such as to excite the admiration of 
every modern physiologist. " C'est un chef-d'oeuvre," 
says a distinguished French physiologist, Flourens, "ce 
petit livre de cent pages est le plus beau livre de la 
physiologic" * 

The discovery made by Harvey was this : That the 
blood passed from the heart into the arteries, thence to 
the veins, by which it was brought back to the heart 
again ; that the blood moved more or less in a circle, 
coming back eventually to the point from which it 
started. In a phrase, there was a Circulation of the 
Blood. Moreover, this circulation was of a double 
nature — one circle being from the right side of the heart 
to the left through the lungs, hence called the Pulmon- 
ary or Lesser Circulation ; the other from the left side 
of the heart to the right, through the rest of the body, 
known as the Systemic or Greater Circulation. Further, 
that it was the peculiar office of the heart to maintain 
this circulation by its continuous rhythmic beating as 
long as life lasts. 

This appears very plain and simple to us now — so 
easy that he who runs may read : as important as 

1 Flourens, Histoire de la Decouverte de la Circulation du Sang, 

Editor's Introduction ix 

simple, for without this knowledge it is no exaggeration 
to say that a real understanding of any important 

function of the human body was impossible. And 
hence it has been contended with much force that not 
only the science of physiology, but the scientific practice 

of medicine date from this discovery. "To medical 
practice," says Sir John Simon, "it stands much in the 
same relation as the discovery of the mariner's compass 
to navigation ; without it, the medical practitioner would 
be all adrift, and his efforts to benefit mankind would 
be made in ignorance and at random. . . . The 
discovery is incomparably the most important ever 
made in physiological science, bearing and destined to 
bear fruit for the benefit of all succeeding ages." ! 

When Harvey first approached the subject, there 
were all kinds of crude and fantastic ideas regarding 
the functions and uses of the heart, bloodvessels, and 
blood — that the heart was the workshop in which 
were elaborated the spirits, a due supply of which was 
necessary for many parts of the body ; that from the 
heart the arteries carried spirits, the veins nutriment to 
the different parts of the body ; that the arteries con- 
tained blood and air mixed together, or only air; that 
fuliginous vapours, whatever they may be, passed from 
the heart along the bloodvessels ; that the septum of the 
heart, by which its two sides are completely separated, 
was riddled with minute holes, like a fine sieve, through 
which the blood percolated from the right to the left 
side ; again, that the heart was the organ in which the 
heat of the body was produced. Another favourite 
theory was that the blood moved from the heart along 
certain bloodvessels and back again by exactly the 
same channels, after the manner of the rise and fall of 
the tides, to which in fact the movement was likened. 
More curious still, even the best informed appeared to 
believe that the arteries terminated in nerves. 

1 Harvey Tercentenary Memorial Meeting, Folkestone, September 6, 

x Editor's Introduction 

Notwithstanding these curious and erroneous specu- 
lations there was not wanting exact and wide knowledge 
of the anatomy of the human body. Indeed, before 
Harvey was born there had lived and died a most 
remarkable man known to fame as the " Father of 
Anatomy." This was Vesalius. Vesalius's knowledge 
of the human body was so profound that the only 
wonder is that he did not forestall Harvey in the 
discovery of the circulation. As the result of dissections 
of the body at the time when they could be carried out 
only with great difficulty, and often at the risk of severe 
penalties, Vesalius published, when only twenty-eight 
years of age, a treatise on Anatomy x which cannot fail 
to excite the astonishment and admiration of any 
modern acquainted with the subject. This work is 
illustrated with fine engravings made from drawings by 
John Calcar, a Flemish artist, and pupil of Titian. 2 

The distribution of the bloodvessels in the lungs 
and many other parts of the body, the general structure 
of the heart, the valves in the veins, were all known 
before Harvey arrived on the scene. More than this, 
the circulation through the lungs, or the Pulmonary 
Circulation, appears to have been known to one person 
at least. Michael Servetus, famous for his martyrdom 
on account of his religious opinions, in one of his 
theological works 3 does actually describe the blood as 
passing from the right side of the heart to the left 
through the lungs, and gives good reasons for his 
belief. Servetus, in his early days, had been with 
Vesalius prosector to John Guinterius of Andernach 
when Professor of Anatomy at Paris. Guinterius 4 
speaks with admiration of the knowledge and abilities 
of his two young assistants. Like Vesalius, Servetus 
was therefore well acquainted with the anatomy of the 
body ; but more, he was a physiologist ; and no doubt 

1 De humani Corporis fabrica, 1543. 

3 Vasari : " Lives of the Painleis," vols. iii. 519, v. 402 (Bohn's ed.). 

* Restitutio Christianismi, 1553. 

* Institutiuues Anatouuoi, Jipistola Nuncupatoria, 1539. 

Editor's Introduction xi 

when the cruelty of th J dispute sent him to the 

stake at the age of forty-tour, it deprived phj 

of a most promising investigator. The book in which 

the account of the Pulmonary Circulation is found has 
B most curious history. All copies of it, except one, 
were burnt with ServetUS. This copy became the pro- 
perty of I>. O>lladon, one of his judges. After passing 
through the library of the Landgrave of Hesse-Cassel 
it came into the hands of a Dr. Mead, who undertook 
in 1723 to issue a quarto edition of it, but before 
completion the sheets were seized at the instance of 
1 >r. Gibson, Bishop of London, and destroyed. The 
Due de Valise is said to have given 400 guineas 
for the original copy, and at his sale it brought 3,810 
livres. It is now in the National Library at Paris. 
It may well be questioned therefore whether the 
discovery of Servetus was ever known to the anatomists, 
including Harvev, who wrote after his death. One of 
these was Realdus Columbus, who published a work 
on Anatomy 1 six years after Servetus died, in which 
he shows that he clearly understood the valves of the 
heart, and describes the passage of the blood through 
the lungs. Columbus has been claimed as the real 
discoverer of the circulation and as having forestalled 
Harvey. But neither Servetus nor Columbus had any 
notion of the Greater or Systemic Circulation. And 
the latter actually says the heart is not muscular, and 
speaks of a to-and-fro movement of the blood in the 

But a third and much more serious precursor of 
Harvey as the discoverer has been brought forward in 
the person of Andreas Caesalpinus 2 of Arezzo, justly 
renowned as the earliest of botanists. He actually- 
used the word " circulation " in regard to the passage of 
the blood through the lungs. The claims of Caesal- 
pinus have been taken up with enthusiasm, not to say 

1 De Re Anatomica, 1559. 

* Quaesliones Peripaleticae, 1569. De Plantis, 15^3. 

xii Editor's Introduction 

bitterness, in Italy; and in 1876 his statue was erected 
with much pomp and speechmaking in Rome, and an 
inscription placed upon it recording that he was the 
first discoverer of the circulation of the blood. It is 
much to be regretted that this display was not alto- 
gether free from a desire to depreciate Harvey. 
Wonder may well be expressed at this procedure, even 
after allowing for well-meant patriotic ardour, when it 
is learnt that in his works Cassalpinus speaks of the 
arteries ending in nerves, of the septum of the heart 
being permeable, and its valves acting imperfectly, and 
of the veins carrying blood to the body for its nourish- 
ment. The statements made by Caesalpinus, which at 
first sight point to his knowledge of the circulation, are 
altogether discounted on perusal of his works, and it 
becomes impossible to believe that he had any clear 
idea of the circulation as we understand it to-day. 
The misconception has no doubt arisen from the 
interpretation of isolated passages in the light of what 
we now know regarding the circulation. Moreover, it 
is impossible to believe, seeing how well the works of 
Caesalpinus were known, that, had he ever been re- 
garded as putting forward in them the doctrine of the 
circulation as we now understand it, such a new and 
startling view would not have attracted the attention of 
the distinguished anatomists who were his contem- 
poraries or immediate successors. But that none of 
them ever for a moment saw any such doctrine in 
the works of Caesalpinus is shown by their writings, 
and by the surprise with which Harvey's discovery 
was received. 

Even Shakespeare has been cited as being acquainted 
with the circulation of the blood, because he refers to 
its movement. This only illustrates the confusion 
which has often been made of movement with cir- 
culation. From the earliest times it had been believed 
there was movement of the blood, but there was no 
clear or correct idea as to the nature of the movement. 

Editor's Introduction xiii 

The view may be ventured that another confusion is 
for a good ileal that has been said about 
Harvey having been forestalled in the discovery. It 
is confusing the passage through the lungs of some 
blood with the whole mass of it. It is difficult to 
believe, on taking a broad view of all their statements 
on the subject, that any of Harvey's predecessors 
realised that the whole mass of the blood was con- 
tinually passing through the lungs. Had they done so 
il is further difficult to see how the systemic circulation 
should have escaped them. But of this they certainly 
had no id' a. 

We may admit all this previous knowledge without 
its detracting from the ureatne^s and merit of Harvey's 
work. Although the same anatomical facts, and even 
a glimmering of the Pulmonary Circulation may have 
hi en present to the minds of his predecessors or con- 
temporaries, yet the genius, the spark of originality by 
which was discovered the proper relation to one another 
of the former, the true significance and meaning of the 
latter, belongs to Harvey and to him alone. 

As was said by one of the best informed minds 1 of 
the eighteenth century: "It is not to Csesalpinus, 
because of some words of doubtful meaning, but to 
Harvey, the able writer, the laborious contriver of so 
many experiments, the staid propounder of all the 
arguments available in his day, that the immortal 
glory of having discovered the Circulation of the Blood 
is to be assigned." 

William Harvey was born on April i, in the year 
1578, at Folkestone, the eldest of seven sons of a 
well-to-do Kentish yeoman. When ten years old he 
was sent to the Grammar School at Canterbury, and re- 
mained there until he was fifteen. He then proceeded 
to Caius College, Cambridge, where after three years' 
residence he took the usual degree. Desiring to 
enter the medical profession, he adopted a course, not 

' Halter, Elementa Physiologiae, vol. i. lib. iii., 1757. 

xiv Editor's Introduction 

unusual at that time, of going abroad to study at a 
Continental University, a course due to the absence 
of scientific teaching in the English Universities on 
the one hand, and to its excellence in those of the 
Continent on the other. Consequently, in the year 
1597, when nineteen years of age, Harvey directed 
his steps towards Padua, then famous throughout 
Europe for its medical school, and especially for its 
school of anatomy. Earlier in the century the chair 
of Anatomy had been filled by Vesalius; it was now 
occupied by another celebrated anatomist, known as 
Fabricius of Aquapendente. Harvey enjoyed the 
advantage of studying anatomy under this great 
teacher, and the visitor to Padua to-day can see the 
little anatomical theatre with its carved desks, over 
one of which, no doubt, our illustrious discoverer leant 
with eager attention whilst Fabricius demonstrated on 
the body below. We can see the professor with pride 
explaining to his pupils the valves in the veins which 
he had discovered, yet not appreciating their meaning 
and importance ; that was to be done a few years hence 
by the young student listening above. It is very 
interesting to learn that at this time Galileo was also 
a professor at Padua, and was lecturing with such 
success that students flocked to hear him from all 
parts of Europe. Surely it is difficult to imagine any 
seat of learning more distinguished and attractive than 
the University of Padua must have been during the 
five years Harvey spent there. At the end of this 
time he received his degree of doctor, the diploma for 
which is couched in the most eulogistic language, 
showing how by his studies and abilities he had 
attracted the attention and earned the commendation 
of the distinguished professors who then held the 
chairs of Anatomy, Medicine, and Surgery in the Uni- 
versity. He now returned to England, and was 
granted the degree of Doctor of Medicine by the 
University of Cambridge. 

Editor's Introduction xv 

Soon after, Harvey settled in London and began to 

practise. In 1607 he was elected a Fellow of the 

Royal College of Physicians, and in 16 15 was ap- 
pointed Lecturer in Anatomy to that ancient and 
important foundation. In 1609 he had been elected 
physician to St. Bartholomew's Hospital. 

In 1616, the year Shakespeare died, Harvey probably 
began in his classes to teach that doctrine which has 
immortalised his name. He began to show his pupils, 
and whoever else desired to be present, from dis- 
sections of the human body and of animals, and by 
experiment when necessary, the true office of the 
heart, the true course of the movement of the blood 
in the body. This he continued to do for more 
than ten years, listening patiently to objections, indeed 
inviting criticisms so that the complete truth might 
be discovered free from any falsities or misconceptions. 
At last, upon the earnest entreaties of his most dis- 
tinguished medical friends, he was persuaded to 
publish his discovery to the world. These facts are 
of interest in throwing some light on Harvey's character. 
A discoverer who waits years before publishing what 
he is firmly convinced in his own mind is a new idea, 
not to say a great discovery, must be possessed of that 
calmness of mind and abnegation of self which we 
associate with the true philosopher. A discoverer who 
employs so long an interval to give opportunity for 
criticism, and to deal with objections, must indeed be 
wedded to truth. 

This devotion to truth, however, had its reward, for 
it resulted in one of the most remarkable scientific 
treatises ever written. When, in 1628, Harvey pub- 
lished at Frankfort-on-Main, his book on "The Move- 
ment of the Heart and Blood," he gave his reasons 
for believing the blood to circulate, and explained the 
use of the heart in language so simple, so clear, so 
exact, that now, nearly three hundred years afterwards, 
the most accomplished physiologist can hardly improve 
b :6J 

xvi Editor's Introduction 

on it. This assuredly is a fact almost unique in the 
history of science. 

And yet with all this the fact remains that Harvey 
never really knew, from the nature of the case could 
not know, how the blood passed from the arteries 
to the veins — how, in other words, an essential part 
of the circulation was actually accomplished. The 
blood passes from the arteries to the veins through 
minute microscopic tubes termed capillaries. In 
Harvey's day the microscope was not sufficiently 
powerful to reveal such fine structures to human vision, 
and he was therefore necessarily ignorant of their 
existence. Looked at from this point of view, the 
discovery affords a very good example of what has 
been aptly termed the scientific use of the imagination. 
Although, with his imperfect microscope, it was im- 
possible for him to know how the blood actually 
passed from the arteries to the veins, yet as the result 
of his observations and experiments he was able to 
infer and to state the grounds for his inference in clear, 
forcible, and most convincing language, that the blood 
must circulate, and circulate in one direction only, viz. 
from the heart into the arteries, thence to the veins, 
by which it was brought back to the heart again. 
His imagination was thus enabled to bridge over the 
gulf between the arteries and veins which his eyes, 
with the imperfect instrument then alone at his disposal, 
were quite unable to cross. It was not until four 
years after Harvey's death that the microscope had 
been sufficiently improved to enable an Italian anato- 
mist named Malpighi, 1 in the year 1661, to actually 
observe the capillaries uniting by their networks arteries 
and veins. 

The work was published at Frankfort doubtless that 
it might be more easily disseminated over the Con- 
tinent. It made a sensation among the learned of all 
countries. Its conclusions were opposed by the older 

1 De Pulmcn bus, Observations Anatomici, 1663. 

Editor's Introduction xvii 

physicians; but by the younger scientific men it was 
by no means received with disfavour. Amongst the 
latter was the philosopher Descartes, whose name was 
then a power in Europe. The philosophical, yet keenly 
practical mind of Descartes grasped the discovery with 
avidity and supported it with ardour In his celebrated 
" Discours de la Methode," l he refers to the discovery of 
" an English physician," and describes with enthusiasm 
the anatomy and use of the heart. Although we have 
no certain information on the point it is quite possible 
that 1 >escartes may have known Harvey, for in the year 
1631 he is said to have paid a visit to England ; and 
in his second reply to Riolan Harvey refers to " the 
ingenious and acute Descartes," and says the honourable 
mention of his name demands his acknowledgments. 
Thus the discovery became widely known and largely 

One result of the publication of his discovery was 
only in keeping with the experience of many great and 
original minds before and after his time. In the things 
of this world his discovery was of little service to him. 
His practice fell off. Patients feared to put themselves 
under the care of one who was accused by his envious 
detractors of being crack-brained, and of putting forward 
new-fangled and dangerous doctrines. One who knew 
Harvey writes as follows : " I have heard him say that 
after his booke of the Circulation of the Blood came 
out he fell mightily in his practice, and 'twas believed 
by the vulgar that he was crack-brained, and all the 
physitians were against him, with much adoe at last in 
about 20 or 30 years time it was received in all the 
universities in the world, and as Mr Hobbs says in 
his book ' De Corpore,' he is the only man perhaps that 
ever lived to see his own doctrine established in his 
lifetime." 2 

There was one striking exception to this treatment. 

1 First published at Leyden in 4to, 1637. 

'John Aubrey, " Lives and Letters ot Eminent Persons," London, 1813. 

xviii Editor's Introduction 

The King, Charles I., not only appointed Harvey his 
physician, but showed the liveliest interest in his dis- 
covery. Harvey explained his new doctrine on the 
body before the King. Whatever opinions may be held 
regarding the moral and political character of that 
unfortunate monarch, it must be admitted that in aiding 
and befriending Vandyke and Harvey he showed him- 
self an enlightened patron of both art and science. 
Harvey continued the King's physician, and held this 
position when, in 1641, Charles declared war against the 
Parliament. It is here curious to learn that although 
openly declared enemies the Parliament was still 
mindful of the King's person, for not only with their 
consent, but by their desire, Harvey remained his 
physician. 1 Notwithstanding his intimate connection 
with the Court, Harvey appears to have taken no active 
part in the great political struggle now taking place. The 
little solicitude he had for it is shown by an anecdote 
told of him at the first battle of the Civil War. " When 
King Charles," says a contemporary author, 2 " by reason 
of the tumults left London, Harvey attended him, and 
was at the fight of Edgehill with him : and during the 
fight the Prince and the Duke of York were committed 
to his care. He told me that he withdrew with them 
under a hedge, and tooke out of his pocket a booke and 
read. But he had not read very long before a bullet of 
a great gun grazed on the ground near him, which made 
him remove his station." This anecdote well illustrates 
Harvey's calm and peaceful character. This was also 
shown by the restrained and dignified manner in which 
he treated the many writers who attacked him, some- 
times in anything but choice language, after the 
publication of his great discovery. Anything like 
controversy for controversy's sake was wholly foreign 
to his nature. "To return evil speaking with evil 
speaking," he remarks in a reply to one of his critics, 

' De Generatione Ex. lxviii. 
* Aubrey, loc. cit. 

Editor's Introduction xix 

" I hold to be unworthy of a philosopher and a searcher 
after truth. I believe I shall do better and more 
advisedly if I meet so many indications of ill breeding 
with the light of faithful and conclusive observation." » 
To many of the attacks made on his discovery or on 
himself, he therefore did not condescend to reply. And 
when from the eminence of his opponents he felt called 
upon to do so, he replied with the utmost courtesy and 
kindliness. But whilst admitting the high claims to 
distinction on other grounds of his antagonist, he pro- 
ceeded on this particular question to utterly demolish 
him with clear facts and stern irrefutable arguments 
and experiments. He called upon his opponents to 
observe the facts and make the experiments for them- 
selves, instead of citing the opinions of authors centuries 
old, or making long discourses on spirits, fuliginous 
vapours, and the tides of Euripus. This is well illus- 
trated in his replies to Riolan. The arguments of 
Riolan would hardly seem to have entitled him to the 
honour of the special notice of the great discoverer. 
But probably his position as Anatomist in the University 
of Paris, and of physician to the Queen-Mother, Marie 
de Medicis, made Harvey pick out his criticisms as a 
suitable excuse for replying to his opponents. Harvey's 
mode of argument is well shown by the following 
admirable remarks on the Manner and Order of Acquir- 
ing Knowledge, in his introduction to the work on 
"The Generation of Animals " : "Sensible things are of 
themselves and antecedent ; things of intellect however 
are consequential and arise from the former, and indeed 
we can in no way attain to them without the help of 
the others. And hence it is that without the due 
admonition of the senses, without frequent observation 
and reiterated experiment, our mind goes astray after 
phantoms and appearances. Diligent observation is 
therefore requisite in every science, and the senses are 
to be frequently appealed to. We are, I say, to strive 

' Vide Second Reply to Riolan, p. 133 post. 

xx Editor's Introduction 

after personal experience, not to rely on the experience 
of others: without which indeed no one can properly 
become a student of any branch of natural science." 
Referring to his own particular work he says : " I would 
not have you therefore, gentle reader, to take anything 
on trust from me concerning the Generation of Animals : 
I appeal to your own eyes as my witness and judge. 
For as all true science rests upon those principles which 
have their origin in the operation of the senses, par- 
ticular care is to be taken that by repeated dissection 
the grounds of our present subject be fully established. 
. . . The method of investigating truth commonly 
pursued at this time therefore is to be held erroneous 
and almost foolish, in which so many inquire what 
others have said, and omit to whether the things 
themselves be actually so or not." 

When the King made Oxford his headquarters, 
Harvey was with him, and was appointed head of 
Merton College. But in 1646, on Oxford surrender- 
ing to the Parliamentary forces, he gave up his warden- 
ship and quitted the city. Having no call to take an 
active part in the political contest, and now verging 
on threescore-and-ten, he retired from his position 
of physician to the King and went to London, where 
he was hospitably entertained in the houses of his 
brothers, who were wealthy merchants in the City. 
Here he no doubt once again devoted himself to 
scientific observation, the nature of which became 
evident, when in 1651 he was persuaded, somewhat 
against his own inclination, by his friend, Dr. George 
Ent, to allow the publication of his book on " The 
Generation of Animals." In this work he appears as 
a pioneer in the difficult science of Embryology, 
working under most adverse conditions, for he had 
no microscope worthy of the name. Whilst, therefore, 
of no great value in the light of our present know- 
ledge, it is a monument of the author's industry and 
of his enthusiastic devotion to physiological research. 

Editor's Introduction xxi 

It contains a great number of acute and interesting 
observations; and he had evidently made man)- more, 
for he says that his papers on the Generation of 

Insects were lost as a result of the tumults which 
arose at the outbreak of the Civil War. He told 
Aubrey that no grief was so crucifying to him as the 
loss of these papers. The King took a direct personal 
interest in these investigations, 1 and supplied him with 
deer from the Royal Parks in order to further them. 

In two respects the work on Generation is worthy 
of more than a mere passing notice, and entitles its 
author to the possession of almost prophetic genius. 
The first is the enunciation of the great generalisation 
otnnt vivum ex OVO. Although this particular phrase 
is nowhere to be found, as is often erroneously stated, 
in the treatise on Generation, yet a perusal of Exer- 
cises I., LI., and LXII. will convince any one that 
Harvey had grasped this great idea, which has since 
been so abundantly verified. The other is his doctrine 
of Epigenesis, or the formation of the new organism 
from the homogeneous substance of the germ by the 
successive differentiation of parts, that all parts are 
not formed at once and together, but in succession 
one after the other He put forward this doctrine of 
Epigenesis in contradistinction to that oi Metamorphosis, 
according to which the germ was suddenly transformed 
into a miniature of the whole organism which subse- 
quently grew. This is certainly very remarkable, and 
entitles him to be regarded as a forerunner of Caspar 
Wolff, Von Baer, and the modern Evolutionary School, 
which sees in the development of the organism from 
the ovum a passage from the homogeneous to the 
heterogeneous by a gradual process of differentiation, 
from a germ in which there is no sign of any of the 
parts of the adult to an organism with all its many 
and varied organs. Commenting on certain passages 
of Exercise XLY., in which Harvey specially refers 

1 De Generatione Ex. lxix. 

xxii Editor's Introduction 

to this subject, the late Professor Huxley' remarked : 
" In these words, by the divination of genius, Harvey 
in the seventeenth century summarised the outcome 
of the work of all those who, with appliances he could 
not dream of, are continuing his labours in the 
nineteenth century." 1 

In addition to his long sojourn in Italy as a student, 
Harvey made several other visits to the Continent. In 
1630 he consented to accompany the young Duke of 
Lennox in his travels abroad. He had returned by 
1632, for in that year he was formally appointed 
physician to Charles I. Again, in 1636 he accom- 
panied the Earl of Arundel on his embassy to the 
Emperor, and was absent some nine months. Accord- 
ing to Aubrey, in 1649 Harvey, with his friend Dr. 
George Ent, again visited Italy. Some doubt has 
been thrown on this journey, but it receives support 
from a letter of Harvey's to John Nardi, of Florence, 
written on November 30, 1653, in which he concludes 
by asking his correspondent to mention his name 
to his Serene Highness the Duke of Tuscany, " with 
thankfulness for the distinguished honour he did me 
when I was formerly in Florence." 

In his old age Harvey was honoured in a striking 
manner by those best fitted to judge of the merit and 
value of his life's work. His statue was erected in the 
hall of the College of Physicians. As an acknowledg- 
ment, as it were, of this remarkable compliment, he 
built at his own expense a Convocation Hall and a 
Library as additions to the College, and contributed 
books, curiosities, and surgical instruments for the 
Library and Museum. Not content with this, he 
made over to the College, the year before he died, 
his paternal estate, stipulating that a certain sum out 
of it should be employed every year for the delivery 
of an Oration in commemoration of benefactors of 
the College, and of those who had added anything 

1 Evolution : " Encyclopaedia Britannica," 9th ed. 1378. 

Iuli tor's Introduction xxiii 

'.o medical knowledge during the year. This Oration 

S annually delivered by some distinguished member 
of the medical profession, and is inseparably associated 
with the name of Harvey. This graceful act shows 
how in his declining years Harvey's thoughts were 
turned to the future. It had for its object to further 
the progress of scientific knowledge, to stimulate studies 
in the pursuit of which he had shown himself such a 
master. He wished when old and infirm, bereft of 
the power of again entering the arena of active work 
and investigation, to still do something to increase and 
extend that knowledge which is of so great service to 
mankind — a knowledge of the human body in health 
and in disease. 

Harvey died on June 3, in the year 1657, in the 
eightieth year of his age, and was buried at the 
village of Hempstead, in Essex, in a vault which had 
been built by his brother Eliab. 

E. A. Parkvn. 

Lovdon, h'ovembo, 1 906. 

xxiv Editors Introduction 

The following is a list of Harvey's works, and of the 
more important references to his life and discovery: — 

"MS. Memorandum Book," dated 1616, entitled "Prse- 
lectiones Anatomical Universalis." It is in Harvey's 
handwriting, and contains the origin of the Circulation. 
(In the British Museum.) A Facsimile was published in 
1886 by the College of Physicians. 

"MS. De Musculis," 1627, in Harvey's handwriting. 
(Brit. Mus.) A Notice on this manuscript was published 
in 1850 by G. E. Paget, M.D. 

"MS. of Prescriptions," 1647. (Brit. Mus.) 

"MS. Diploma of Doctor of Medicine" to Harvey by 
University of Padua, April 25, 1602. (In the College of 

" MS. Illuminated Grant of M.D.," by Universityof Padua 
to an Englishman, Thomas Heron, which is witnessed by 
"Guigliomo Harveo Consiliaris Magniricas NationisAnglae/ 
It is dated March 19, 1602. (Brit. Mus.) 

" MS. Oratio Harveiana," 1661, ab. E. Greaves. (Brit. 

"De Motu Cordis et Sanguinis," Frankfort-on-Main, 
1628. First English edition published by R. Lowndes, 
with preface by Zachariah Wood, Physician of Rotter- 
dam, 1653. 

" Anatomical Examination of the Body of Thomas Parr, 
aged 1 52 years," made in 1635, but not published until 1669 
in Betts' " De Ortu et Natura Sanguinis." 

" Two Disquisitions in Reply to John Riolan, jun.," 1649. 

" De Generatione Animalium," London, 165 1 ; in 
English, 1653. 

" Biogvaphica Britannica," 1750. The Life of Harvey, 
containing much curious information and discussion, is 

Editor's Introduction xxv 

evidently that on which all subsequent biographies aie 

•• Harveii Opera Omnia,* 1 edited by Dr. Akenside, with 
Life by Thomas Lawrence, M.D., 1766. 

" Lives and Letters of Eminent Persons," by John 
Aubrey, 181 3. 

-Records of William Harvey, with Notes," by James 
et, of St Bartholomew's Hospital, 184''). 

"The Works of William Harvey," translated by Robert 
Willis, M.D. (Sydenham Society, 1848). This excellent 
translation has been followed in the present volume. 

" Histoire de la Decouverte de la Circulation du Sang," 
par M. J. P. Flourens, 1854. 

"Circulation of the Blood : its History, Cause, and 
Course," by G. H. Lewes in "Physiology of Common 
Life,'' 1S59. 

" Memorials of Harvey," collected by J. H. Aveling, 1875. 

•William Harvey: a history, etc.," by Robert Willis, 
M.D., 1878. 

" Roll of the Royal College of Physicians," by William 
Munk, M.D., 2nd ed., 1S78. 

Huxley on "Evolution," in "Encyclopaedia Britannica," 
9th ed., 1S78. 

"Experimental Physiology," by Sir R. Owen, 1882. 

"A Defence of Harvey," by George Johnson, M.D., 


" Masters of Medicine : William Harvey," by DArcy 

Power 1897. 


In the present edition of Harvey's Treatise on the 
Circulation of the Blood, which is reprinted from the 
Sydenham Society's edition of 1847, the footnotes by 
Willis, the editor and translator of that edition, are 
distinguished by brackets from Harvey's original notes. 

r <ol 



MllBRA^Y } 




















xxviii Table of Contents 



OF THE BLOOD .... -55 















Table of Contents xxix 

CHAP. I-Aoc 



ARE REFUTED ... .131 











xxx Table of Contents 








HARVEY, M.D. . 212 

INDEX 223 




c 2& » 





king of great britain, france, and ireland 
defender of the faith 

Most illustrious Prince ! 

The heart of animals is the foundation of their 
life, the sovereign of everything within them, the 
sun of their microcosm, that upon which all growth 
depends, from which all power proceeds. The King, 
in like manner, is the foundation of his kingdom, 
the sun of the world around him, the heart of the 
republic, the fountain whence all power, all grace 
doth flow. What I have here written of the motions 
of the heart I am the more emboldened to present 
to your Majesty, according to the custom of the 
present age, because almost all things human are 
done after human examples, and many things in a 
King are after the pattern of the heart. The know- 
ledge of his heart, therefore, will not be useless to a 
Prince, as embracing a kind of Divine example of 
his functions, — and it has still been usual with men 


4 To Prince Charles 

to compare small things with great. Here, at all 
events, best of Princes, placed as you are on the 
pinnacle of human affairs, you may at once con- 
template the prime mover in the body of man, and 
the emblem of your own sovereign power. Accept 
therefore, with your wonted clemency, I most humbly 
beseech you, illustrious Prince, this, my new Treatise 
on the Heart : you, who are yourself the new light 
of this age, and indeed its very heart ; a Prince 
abounding in virtue and in grace, and to whom we 
gladly refer all the blessings which England enjoys, 
all the pleasure we have in our lives. 

Your Majesty's most devoted servant, 

William Harvey. 
London, 1628. 

To his very dear Friend, DOCTOR ARGENT, 
the excellent and accomplished President 
of the Royal College of Physicians, and to 

other learned Physicians, his most esteemed 


I have already and repeatedly presented you, my 
learned friends, with my new views of the motion 
and function of the heart, in my anatomical lectures ; 
but having now for nine years and more confirmed 
these views by multiplied demonstrations in your 
presence, illustrated them by arguments, and freed 
them from the objections of the most learned and 
skilful anatomists, I at length yield to the requests, 
I might say entreaties, of many, and here present 
them for general consideration in this treatise. 

Were not the work indeed presented through you, 
my learned friends, I should scarce hope that it could 
come out scatheless and complete ; for you have in 
general been the faithful witnesses of almost all the 
instances from which I have either collected the truth 
or confuted error ; you have seen my dissections, 
and at my demonstrations of all that I maintain to 
be objects of sense, you have been accustomed to 


6 Dedication 

stand by and bear me out with your testimony, 
And as this book alone declares the blood to course 
and revolve by a new route, very different from the 
ancient and beaten pathway trodden for so many 
ages, and illustrated by such a host of learned and 
distinguished men, I was greatly afraid lest I might 
be charged with presumption did' I lay my work 
before the public at home, or send it beyond seas 
for impression, unless I had first proposed its subject 
to you, had confirmed its conclusions by ocular 
demonstrations in your presence, had replied to your 
doubts and objections, and secured the assent and 
support of our distinguished President. For I was 
most intimately persuaded, that if I could make good 
my proposition before you and our College, illustrious 
by its numerous body of learned individuals, I had 
less to fear from others ; I even ventured to hope 
that I should have the comfort of finding all that 
you had granted me in your sheer love of truth, 
conceded by others who were philosophers like your- 
selves. For true philosophers, who are only eager 
for truth and knowledge, never regard themselves as 
already so thoroughly informed, but that they welcome 
further information from whomsoever and from whence- 
soever it may come; nor are they so narrow-minded 
as to imagine any of the arts or sciences transmitted 
to us by the ancients, in such a state of forwardness 
or completeness, that nothing is left for the ingenuity 
and industry of others ; very many, on the contrary, 

Dedication 7 

maintain that all we know is still infinitely less than 
all that still remains unknown : nor do philosophers 
pin their faith to others' precepts in such wise that 
they lose their liberty, and cease to give credence to 
the conclusions of their proper senses. Neither do 
they swear such fealty to their mistress Antiquity, 
that they openly, and in sight of all, deny and d( 
their friend Truth. But even as they see that the 
credulous and vain are disposed at the first blush to 
accept and to believe everything that is proposed to 
them, so do they observe that the dull and unintel- 
lectual are indisposed to see what lies before their 
eyes, and even to deny the light of the noonday 
sun. They teach us in our course of philosophy as 
sedulously to avoid the fables of the poets and the 
fancies of the vulgar, as the false conclusions of 
the sceptics. And then the studious, and good, and 
true, never suffer their minds to be warped by the 
passions of hatred and envy, which unfit men duly 
to weigh the arguments that are advanced in behalf 
of truth, or to appreciate the proposition that is even 
fairly demonstrated ; neither do they think it unworthy 
of them to change their opinion if truth and un- 
doubted demonstration require them so to do; nor 
do they esteem it discreditable to desert error, though 
sanctioned by the highest antiquity ; for they know 
full well that to err, to be deceived, is human ; that 
many things are discovered by accident, and that many 
may be learned indifferently from any quarter, by an 

8 Dedication 

old man from a youth, by a person of understanding 
from one of inferior capacity. 

My dear colleagues, I had no purpose to swell 
this treatise into a large volume by quoting the 
names and writings of anatomists, or to make a 
parade of the strength of my memory, the extent of 
my reading, and the amount of my pains ; because 
I profess both to learn and to teach anatomy, not 
from books but from dissections ; not from the posi- 
tions of philosophers but from the fabric of nature ; 
and then because I do not think it right or proper 
to strive to take from the ancients any honour that 
is their due, nor yet to dispute with the moderns, 
and enter into controversy with those who have 
excelled in anatomy and been my teachers, I would 
not charge with wilful falsehood any one who was 
sincerely anxious for truth, nor lay it to any one's 
door as a crime that he had fallen into error. I 
avow myself the partisan of truth alone ; and I can 
indeed say that I have used all my endeavours, 
bestowed all my pains on an attempt to produce 
something that should be agreeable to the good, 
profitable to the learned, and useful to letters. 
Farewell, most worthy Doctors, 

And think kindly of your Anatomist, 

William Harvey. 





As we are about to discuss the motion, action, and use 
of the heart and arteries, it is imperative on us first to 
state what has been thought of these things by others 
in their writings, and what has been held by the vulgar 
and by tradition, in order that what is true may be 
confirmed, and what is false set right by dissection, 
multiplied experience, and accurate observation. 

Almost all anatomists, physicians, and philosophers, 
up to the present time, have supposed, with Galen, that 
the object of the pulse was the same as that of respira- 
tion', and only differed in one particular, this being 
conceived to depend on the animal, the respiration on 
the vital faculty ; the two, in all other respects, whether 
with reference to purpose or to motion, comporting 
themselves alike. Whence it is affirmed, as by 
Hieronymus Fabricius of Aquapendente, in his book 
on " Respiration," which has lately appeared, that as 
the pulsation of the heart and arteries does not suffice 
for the ventilation and refrigeration of the blood, there- 
fore were the lungs fashioned to surround the heart. 
From this it appears, that whatever has hitherto been 
said upon the systole and diastole, on the motion of 


io On the Heart and Blood 

the heart and arteries, has been said with especial 
reference to the lungs. 

But as the structure and movements of the heart, 
differ from those of the lungs, and the motions of the 
arteries from those of the chest, so seems it likely that 
other ends and offices will thence arise, and that the 
pulsations and uses of the heart, likewise of the arteries, 
will differ in many respects from the heavings and uses 
of the chest and lungs. For did the arterial pulse and 
the respiration serve the same ends ; did the arteries in 
their diastole take air into their cavities, as commonly 
stated, and in their systole emit fuliginous vapours by 
the same pores of the flesh and skin ; and further, did 
they, in the time intermediate between the diastole and 
the systole, contain air, and at all times either air, or 
spirits, or fuliginous vapours, what should then be said 
to Galen, who wrote a book on purpose to .show thatJoy 
nature the arteries contained blood, and nothing but 
blood ; neither .spirits nor air, consequently, as may be 
readily gathered from the experiments and reasonings 
contained in the same book ? Now if the arteries are 
filled in the diastole with air then taken into them (a 
larger quantity of air penetrating when the pulse is large 
and full), it must come to pass, that if you plunge into 
a bath of water or of oil when the pulse is strong and 
full, it ought forthwith to become either smaller or 
much slower, since the circumambient bath will render 
it either difficult or impossible for the air to penetrate. 
In like manner, as all the arteries, those that are deep- 
seated as well as those that are superficial, are dilated 
at the same instant, and with the same rapidity, how 
were it possible that air should penetrate to the deeper 
parts as freely and quickly through the skin, flesh, and 
other structures, as through the mere cuticle ? And 
how should the arteries of the foetus draw air into their 
cavities through the abdomen of the mother and the 
body of the womb? And how should seals, whales, 
dolphins, and other cetaceans, and fishes of every 

Introduction i I 

description, living in the depths of the sea, take in 
and emit air by the diastole and systole of their arteries 
through the infinite mass of waters ? For to say that 
they absorb the air that is infixed in the water, and emit 
their fumes into this medium, were to utter something 
very like a mere figment. And if the arteries in their 
systole expel fuliginous vapours from their cavities 
through the pores of the flesh and skin, why not the 
spirits, which are said to be contained in these vessels, 
at the same time, since spirits are much more subtile 
than fuliginous vapours or smoke? And further, if the 
arteries take in and cast out air in the systole and 
diastole, like the lungs in the process of respiration, 
wherefore do they not do the same thing when a wound 
is made in one of them, as is done in the operation 
of arteriotomy ? When the windpipe is divided, it is 
sufficiently obvious th; t the air enters and returns 
through the wound by two opposite movements ; but 
when an artery is divided, it is equally manifest that 
blood escapes in one continuous stream, and that no 
air either enters or issues. If the pulsations of the 
arteries fan and refrigerate the several parts of the body 
as the lungs do the heart, how comes it, as is commonly 
said, that the arteries carry the vital blood into the 
different parts, abundantly charged with vital spirits, 
which cherish the heat of these parts, sustain them 
when asleep, and recruit them when exhausted ? and 
how should it happen that, if you tie the arteries, 
immediately the parts not only become torpid, and 
frigid, and look pale, but at length cease even to be 
nourished ? This, according to Galen, is because they 
are deprived of the heat which flowed through all parts 
from the heart, as its source ; whence it would appear 
that the arteries rather carry warmth to the parts than 
serve for any fanning or refrigeration. Besides, how 
can the diastole [of the arteries] draw spirits from the 
heart to warm the body and its parts, and, from without, 
means of cooling or tempering them ? Still further, 

12 On the Heart and Blood 

although some affirm that the lungs, arteries, and heart 
have all the same offices, they yet maintain that the 
heart is the workshop of the spirits, and that the arteries 
contain and transmit them ; denying, however, in oppo- 
sition to the opinion of Columbus, that the lungs can 
either make or contain spirits ; and then they assert, 
with Galen, against Erasistratus, that it is blood, not 
spirits, which is contained in the arteries. 

These various opinions are seen to be so incongruous 
and mutually subversive, that every one of them is not 
unjustly brought under suspicion. That it_is blood and 
blood alone which is contained in the arteneirls - hTade 
manifest by the experiment of Galen, by arteriotomy, 
and by wounds ; for from a single artery divided, as 
Galen himself affirms in more than one place, the whole 
of the blood may be withdrawn in the course of half 
an hour, or less. The experiment of Galen alluded to is 
this : " If you include a ,porUaD.._of_an_artery between 
two ligatures, and slit it-ope^4eftg4hwaySy-yeu--will find 
nothing butl5Tood; ,r and thus _he j^ovesjthaLthe .arteries 
contain blood only. And we too may be permitted to 
procee3"by"a like train of reasoning : if we find the same 
blood in the arteries that we find in the veins, which we 
have tied in the same way, as I have myself repeatedly 
ascertained, both in the dead body and in living animals, 
we may fairly conclude that the arteries contain the same 
blood as the veins, and nothing but the same blood. 
Some, whilst they attempt to lessen the difficulty here, 
affirming that the blood is spirituous and arterious, 
virtually concede that the office of the arteries is to 
carry blood from the heart into the whole of the body, 
and that they are therefore filled with blood ; for 
spirituous blood is not the less blood on that account. 
And then no one denies that the blood as such, even 
the portion of it which flows in the veins, is imbued with 
spirits. But if that portion which is contained in the 
arteries be richer in spirits, it is still to be believed that 
these spirits are inseparable from the blood, like those 

Introduction 13 

in the veins : that the blood and spirits constitute one 
body (like whey and butler in milk, or heat [and water] 
in hot water), with which the arteries are charged, and 
for the distribution of which from the heart they are 
provided, and that this body is nothing else than blood. 
But if this blood be said to be drawn from the heart 
into the arteries by the diastole of these vessels, it is 
then assumed that the arteries by their distension are 
rilled with blood, and not with the ambient air, as here- 
tofore ; for if they be said also to become filled with air 
from the ambient atmosphere, how and when, I ask, 
can they receive blood from the heart? If it be 
answered : during the systole ; I say, that seems im- 
possible ; the arteries would then have to fill whilst 
they contracted ; in other words, to fill, and yet not 
become distended. But if it be said : during the 
diastole, they would then, and for two opposite pur- 
poses, be receiving both blood anr" air, and heat and 
cold ; which is improbable. Further, when it is 
affirmed that the diastole of the heart and arteries 
is simultaneous, and the systole of the two is also 
concurrent, there is another incongruity. For how can 
two bodies mutually connected, which are simulta- 
neously distended, attract or draw anything from one 
another; or, being simultaneously contracted, receive 
anything from each other ? And then, it seems im- 
possible that one body can thus attract another body 
into itself, so as to become distended, seeing that to be 
distended is to be passive, unless, in the manner of a 
sponge, previously compressed by an external force, 
whilst it is returning to its natural state. But it is 
difficult to conceive that there can be anything of this 
kind in the arteries. The arteries dilate, because they 
are filled like bladders or leathern bottles; they are not 
filled because they expand like bellows. This I think 
easy of demonstration; and indeed conceive that I have 
already proved it. Nevertheless, in that book of Galen 
headed " Quod Sanguis continetur in Arteriis," he quotes 

14 On the Heart and Blood 

an experiment to prove the contrary : An artery having 
been exposed, is opened longitudinally, and a reed or 
other pervious tube, by which the blood is prevented 
from being lost, and the wound is closed, is inserted 
into the vessel through the opening. "So long," he 
says, " as things are thus arranged, the whole artery 
will pulsate ; but if you now throw a ligature about the 
vessel and tightly compress its tunics over the tube, you 
will no longer see the artery beating beyond the ligature." 
I have never performed this experiment of Galen's, nor 
do I think that it could very well be performed in the 
living body, on account of the profuse flow of blood 
that would take place from the vessel which was 
operated on ; neither would the tube effectually close 
the wound in the vessel without a ligature; and I cannot 
doubt but that the blood would be found to flow out 
between the tube and the vessel. Still Galen appears 
by this experiment to prove both that the pulsative 
faculty extends from the heart by the walls of the 
arteries, and that the arteries, whilst they dilate, are 
filled by that pulsific force, because they expand, like 
bellows, and do not dilate because they'are filled like 
skins. But the contrary is obvious in arteriotomy and 
in wounds; for the blood spurting from the- arteries 
escapes _with__force, now farther, now not so far, alter- 
nately, or in jets ; and the jet always takes place with 
the diastole of the artery, never with the systole. By 
which it clearly appears that the artery is dilated by the 
impulse of the blood ; for of itself it would not throw 
the blood to such a distance, and whilst it was dilating; 
it ought rather to draw air into its cavity through the 
wound, were those things true that are commonly stated 
concerning the uses of the arteries. Nor let the thick- 
ness of the arterial tunics impose upon us, and lead us 
to conclude that the pulsative property proceeds along 
them from the heart. For in several animals the arteries 
do not apparently differ from the veins; and in extreme 
parts of the body, where the arteries are minutely sub- 

Introduction 15 

divided, as in the brain, the hand, &C, no one could 
distinguish the arteries from the veins by the dissimilar 
characters of their coats ; the tunics of both are identical. 
And then, in an aneurism proceeding from a wounded 
or eroded artery, the pulsation is precisely the same as 
in the other arteries, and yet it has no proper arterial 
tunic. This the learned Riolanus testifies to, along 
with me, in his Seventh Book. 

N r let any one imagine that the uses of the pulse 
and the respiration are the same, because under the of the same causes, such as running, anger, 
the warm bath, or any other heating thing, as Galen 
says, they become more frequent and forcible together. 
. not only is experience in opposition to this idea, 
though Galen ende avours to e xplain it a way, when we 
see that with excessive repletion the pulse beats more 
for cibly^ w hilst the respiration is diminished in amount; 
but in young persons the pulse is quick, whilst 
respiration is slow. So is it also in alarm, and amidst 
care, and under anxiety of mind ; sometimes, too, in 
fevers, the pulse is rapid, but the respiration is slower 
than usual. 

These and other objections of the same kind may be 
urged against the opinions mentioned. Nor are the 
views that are entertained of the offices and pulse of 
the heart, perhaps, less bound up with great and most 
inextricable difficulties. The heart, it is vulgarly said, 
is the fountain and workshop of the vital spirits, the 
centre from whence life is dispensed to the several 
parts of the body ; and yet it is denied that the right 
ventricle makes spirits ; it is rather held to supply 
nourishment to the lungs ; whence it is maintained that 
fishes are without any right ventricle (and indeed every 
animal wants a right ventricle which is unfurnished 
with lungs), and that the right ventricle is present 
solely for the sake of the lungs. 

1. Why, I ask, when we see that the structure of 
both ventricles is almost identical, there being the same 

16 On the Heart and Blood 

apparatus of fibres, and braces, and valves, and vessels, 
and auricles, and in both the same infarction of blood, 
in the subjects of our dissections, of the like black 
colour, and coagulated — why. I say ..^should their uses 
be imagined to be different, when the action, motion, 
and pulse of both are the same ? If the three tricuspid 
valves placed at the entrance into the right ventricle 
prove obstacles to the reflux of the blood into the 
vena cava, and if the three semilunar valves which are 
situated at the commencement of the pulmonary artery 
be there, that they may prevent the return of the blood 
into the ventricle ; wherefore, when we find similar 
structures in connexion with the left ventricle, should 
we deny that they are there for the same end, of 
preventing here the egress, there the regurgitation of 
the blood ? 

2. And again, when we see that these structures, in 
point of size, form, and situation, are almost in every 
respect the same in the left as in the right ventricle, 
wherefore should it be maintained that things are here 
arranged in connexion with the egress and regress of 
spirits, there, i.e. in the right, of blood? The same 
arrangement cannot be held fitted to favour or impede 
the motion of blood and of spirits indifferently. 

3. And when we observe that the passages and vessels 
are severally in relation to one another in point of 
size, viz., the pulmonary artery to the pulmonary veins ; 
wherefore should the one be imagined destined to a 
private or particular purpose, that, to wit, of nourishing 
the lungs, the other to a public and general function ? 

4. And, as Realdus Columbus says, how can it be 
conceived that such a quantity of blood should be 
required for the nutrition of the lungs ; the vessel that 
leads to them, the vena arteriosa or pulmonary artery 
being of greater capacity than both the iliac veins ? 

5. And I ask further : as the lungs are so close at 
hand, and in continual motion, and the vessel that 
supplies them is of such dimensions, what is the use 

Introduction 17 

or meaning of the pulse of the right ventricle ? and 
why was nature reduced to the necessity of adding 
another ventricle for the sole purpose of nourishing 
the lungs ? 

When it is said that the left ventricle obtains materials 
for the formation of spirits, air to wi t, and blood, from 
the lungs and right sinuses of the heart, and in like 
manner sends spirituous blo od into the aorta, drawing 
fuliginous vapours tro m~ thenc e, and sending them by 
the arteria venosa into the lungs, whence spirits are at 
the same time obtained for transmission into the aorta, 
I ask h ow, and by what means, i^ thfi se paration 
eff ected ? and how comes it that spirits and fuliginous 
vapours can pass hither and thither without admixture 
or confusion. If the mit ral cuspidate valves d o not 
prevent_ the egre ss of fuliginous vapours to the lungs, 
ho w should they oppose the escape of a ir ? and .how 
shoul d the semilun ar'* hinHpr thp rpgrpss of spirits from 
the aorta upon each supervening diastole of the_heart ? 
ancTTaUove all, how can they say that the spirituous 
blood is sent from the arteria venalis (pulmonary veins) 
by the left ventricle into the lungs without any obstacle 
to its passage from the mitral valves, when they have 
previously asserted that the air entered by the same 
vessel from the lungs into the left ventricle, and have 
brought forward these same mitral valves as obstacles 
to its retrogression ? G ood God ! h o w should the 
mitral valves prevent regurgitation of air and not of 
blood ? 

Further, when t hey d edicate the vena ^arteriosa (or 
pulmonary artery), a vessel of great size, andnaving the 
tunics of an artery, to none but a kind of pr ivate and 
single , purpose, that, namely, of nourishing the lu ngs, 
why should the arteria venalis (or pulmonary vein), 
which is scarcely of similar size, which has the coats of 
a vein, and is soft and lax, be presumed to be made for 
many — three or four, different uses ? For they will 
have it that air passes through this vessel from the 

d 2i2 

18 On the Heart and Blood 

lungs into the left ven tricle : that fuliginous vapours 
escape by it from the heart into the lungs ; and that 
a portion of the spirituous or spiritualized blood is dis- 
tributed by it to the lungs for their refreshment. 

If they will have it that fumes and air — fumes flowing 
from, air proceeding towards the heart— are transmitted 
by the same conduit, I reply, that nature is not wont to 
institute but one vessel, to contrive but one way for 
such contrary motions and purposes, nor is anything 
of the kind seen elsewhere. 

If fumes or fuliginous vapours and air permeate this 
vessel, as they do the pulmonary bronchia, wherefore 
do we find neither air nor fuliginous vapours when we 
divide the arteria venosa ? why do we always find this 
vessel full of sluggish blood, never of air ? whilst in the 
lungs we find abundance of air remaining. 

If any one will perform Galen's experiment of dividing 
the trachea of a living dog, forcibly distending the lungs 
with a pair of bellows, and then tying the trachea 
securely, he will find, when he has laid open the 
thorax, abundance of air in the lungs, even to their 
extreme investing tunic, but none in either the pulmonary 
veins, or left ventricle of the heart. But did the heart 
either attract air from the lungs, or did the lungs 
transmit any air to the heart, in the living dog, by so 
much the more ought this to be the case in the 
experiment just referred to. AYho, indeed, doubts that, 
did he inflate the lungs of a subject in the dissecting- 
room, he would instantly see the air making its way by 
this route, were there actually any such passage for it ? 
But this office of the pulmonary veins, namely, the 
transference of air from the lungs to the heart, is held 
of such importance, that Hieronymus Fabricius, of 
Aquapendente, maintains the lungs were made for the 
sake of this vessel, and that it constitutes the principal 
element in their structure. 

But I should like to be informed wherefore, if the 
pulmonary vein were destined for the conveyance of 

Introduction 19 

air, it ha- the structure of a blood-vessel here. Nature 
had rather need of annular tubes, such as those of the 
\jumv ler that they might always remain open, 

i- : have ! -..en liable to collapse; and that they might 
continue entirely free from blood, lest the liquid should 
interfere with the passage of the air, as it so obviously 
does when the lungs labour from being either greatly 
oppressed or loaded in a less degree with phlegm, as 
they are when the breathing is performed with a sibilous 
or rattling noise. 

Still less is that opinion to be tolerated which (as a 
twofold matter, one aereal, one sanguineous, is required 
for the composition of vital spirits,) supposes the blood 
to ooze through the septum of the heart from the right to 
the left ventricle by certain secret pores, and the air 
to be attracted from the lungs through the great vessel, 
the pulmonary vein; and which will have it, conse- 
quently, that there are numerous, pores in the septum 
cordis adapted for the transmission of the blood. But, 
in faithT'no such pores can be demonstrated, neither in 
fact do any such exist. For the septum of the heart 
is of a denser and more compact structure than any 
portion of the body, except the bones arid sinews. 
But even supposing- that-thei g were foramina or pores 
in this situation, how could one of the ventricles extract 
anything from-the other — the left, e.g., obtain blood from 
therrigTit, when we see that both^y^ntrjij£sxoaitracJ: and 
dilat e simultan eously ? \TTTerelore~should we not rather 
believe that the right took spirits from the left, than 
that the left obtained blood from the right ventricle, 
through these foramina? But it is certainly mysterious 
and incongruous that blood should be supposed to be 
most commodiously drawn through a set of obscure or 
invisible pores, and air through perfectly open passages, 
at one and the same moment. And why, 1 ask, is 
recourse had to secret and invisible porosities, to 
uncertain and obscure channels, to explain the passage 
of the blood into the left ventricle, when there is so 

20 On the Heart and Blood 

open a way through the pulmonary veins ? I own it 
has always appeared extraordinary to me that they 
should have chosen to make, or rather to imagine, a 
way through the thick, hard, and extremely compact 
substance of the septum cordis, rather than to take that 
by the open vas venosum or pulmonary vein, or even 
through the lax, soft, and spongy substance of the lungs 
at large. Besides, if the blood could permeate the 
substance of the septum, or could be imbibed from 
the ventricles, what use were there for the coronary 
artery and vein, branches of which proceed to the 
septum itself, to supply it with nourishment ? And what 
is especially worthy of notice is this : if in the fcetus, 
where everything is more lax and soft, nature saw 
herself reduced to the necessity of bringing the blood 
from the right into the left side of the heart by the 
foramen ovale, from the vena cava through the arteria 
venosa, how should it be likely that in the adult she 
should pass it so commodiously, and without an effort, 
through the septum ventriculorum, which has now 
become denser by age ? 

Andreas Laurentius, 1 resting on the authority of 
Galen 2 and the experience of Hollerius, asserts and 
proves that the serum and pus in empyema, absorbed 
from the cavities of the chest into the pulmonary vein, 
may be expelled and got rid of with the urine and faeces 
through the left ventricle of the heart and arteries. 
He quotes the case of a certain person affected with 
melancholia, and who suffered from repeated fainting 
fits, who was relieved from the paroxysms on passing 
a quantity of turbid, fetid, and acrid urine ; but he died 
at last, worn out by the disease ; and when the body 
came to be opened after death, no fluid like that he had 
micturated was discovered either in the bladder or in 
the kidneys ; but in the left ventricle of the heart and 
cavity of the thorax plenty of it was met with ; and then 

* Lib. ix, cap. xi, quest. 12. 

3 Dc Locis Affectis., lib. vi, cap. 7. 

Introduction 21 

I~iurentius boasts that he had predicted the cause of 
the symptoms. For my own part, however, I cannot 
but wonder, since he had divined and predicted that 
:ogencous matter could be discharged by the course 
he indicates, why he could not or would not perceive, 
and inform us that, in the natural state of things, the 
blood might be commodiuusly transferred from the lungs 
to the left ventricle of the heart by the very same route. 
Since, therefore, from the foregoing considerations 
and many others to the same effect, it is plain that what 
has heretofore been said concerning the motion and 
function of the heart and arteries must appear obscure, 
or inconsistent or even impossible to him who carefully 
considers the entire subject ; it will be proper to look, 
more narrowly into the matter ; to contemplate the 
motion of the heart and arteries, not only in man, but 
in all animals that have hearts ; and further, by frequent 
appeals to vivisection, and constant ocular inspection, 
to investigate and endeavour to find the truth. 






When I first gave my mind to vivisections, as a means 
of discovering the motions and uses of the heart, and 
sought to discover these from actual inspection, and not 
from the writings of others, I found the task so truly 
arduous, so full of difficulties, that I was almost tempted 
to think, with Fracastorius, that the motion of the heart 
was only to be comprehended by God. For I could 
neither rightly oerceive at first when the systole and 
when the diasto^ took place, nor when and where 
dilatation and contraction occurred, by reason of the 
rapidity of the motion, which in many animals is 
accomplished in the twinkling of an eye, coming and 
going like a flash of lightning ; so that the systole pre- 
sented itself to me now from this point, now from that ; 
the diastole the same; and then everything was 
reversed, the motions occurring, as it seemed, variously 
and confusedly together. My mind was therefore 
greatly unsettled, nor did I know what I should myself 
conclude, nor what believe from others ; I was not 
surprised that Andreas Laurentius should have said 
that the motion of the heart was as perplexing as the 
flux and reflux of Euripus had appeared to Aristotle. 

At length, and by using greater and daily diligence, 
having frequent recourse to vivisections, employing a 
variety of animals for the purpose, and collating 
numerous observations, I thought that I had attained 
to the truth, that I should extricate myself and escape 
from this labyrinth, and that I had discovered what I so 
much desired, both the motion and the use of the heart 
and arteries ; since which time I have not hesitated to 


Motion of the Heart and Blood - ; 

e^ pose my \ iews upon these Bubjects, not only in ; 

to my friends but also in public, in my anatomical 

lectures, after the manner of the Academy of old. 

These views, as usual, pleased some more, others 
less ; some chid and calumniated me, and laid it to me as 
a crime that 1 had dared to depart from the precepts 
anil opinion of all anatomists ; others desired further 
explanations of the novelties, which they said were both 
w irthy of consideration, and might perchance be found 
of signal use. At length, yielding to the requests of 
my friends, that all might be made participators in my 
labours, and partly moved by the envy of others, who 

eiving my views with uncandid minds and under- 
standing them indifferently, have essayed to traduce me 
publicly, I have been moved to commit these things to 
the press, in order that all may be enabled to form an 
opinion both of me and my labours. This step I take 
all the more willingly, seeing that Hieronymus Fabricius 
of Aquapendente, although he has accurately and 
learnedly delineated almost every one of the several 
parts of animals in a special work, has left the heart 
alone untouched. Finally, if any use or benefit to this 
department of the republic of letters should accrue from 
my labours, it will, perhaps, be allowed that I have not 
lived idly, and, as the old man in the comedy says : 

For never yet has any one attained 

To such perfection, but that time, and place, 

And use, have brought addition to his knowledge ; 

Or made correction, or admonished him, 

That he was ignorant of much which he 

Had thought he knew ; or led him to reject 

What he had once esteemed of highest price. 

So will it, perchance, be found with reference to the 
heart at this time ; or others, at least, starting from 
hence, the way pointed out to them, advancing under 
the guidance of a happier genius, may make occasion 
to proceed more fortunately, and to inquire more 



In the first place, then, when the chest of a living 
animal is laid open and the capsule that immediately 
surrounds the heart is slit up or removed, the organ is 
seen now to move, now to be at rest j — there is a_time 
whe n it mov es, and a ti me when it is motio nless. 

These things are more obvious in the colder animals, 
such as toads, frogs, serpents, small fishes, crabs, 
shrimps, snails, and shell-fish. They also become more 
distinct in warm-blooded animals, such as the dog and 
hog, if they be attentively noted when the^heart begins 
to flag, to move more slowly, and, as it were, to die : 
the movements then become slower and rarer, the 
pauses longer, by whicTTit is made much more easy to 
perceive and unravel what the motions really are, and 
how they are performed. In the pause, as in death, 
the heart is soft, flaccid, exhausted, lying, as it were, 
at rest. 

In the motion, and interval in which this is accom- 
plished, three principal circumstances are to be noted : 

i. That the heart is erected, and rises upwards to a 
point, so that at this time it strikes, against the breast 
and the pulse is felt externally. 

2. That it is everywhere contracted,^ but more 
especially towards the sides, so that it looks narrower, 
relativel y longer, more drawn to gether. The heart of 
an eel taken out of the body of the animal and placed 
upon the table or the hand, shows these particulars ; 


Motion of the Heart and I Hood 25 

but the same things arc manifest in the heart of small 
fishes and of those colder animals where the organ is 
more conical or elongated. 

3. The heart hcing_ grasped _]n the hand, is felt to 
become harder durin g its action. Now this hardness 
proceeds from tension, precisely as when the forearm is 
grasped, ksTendons are perceived to become tense and 
resilient when the fingers are moved. 

4. It may further be observed in fishes, and the 
colder blooded animals, such as frogs, serpents, &c, 
that the heart, when it moves, becomes of a paler 
colour, when quiescent of a deeper blood-red colour. 

From these particulars it appeared evident to me that 
the motion of the heart consists in a certain universal 
te nsion — both con tractio n in the line of its fibres, and 
constriction in every sense. It becomes erect, hard, 
and of diminished size during its action ; the motion is 
plainly of the same nature as that of the muscles when 
they contract in the line of their sinews and fibres ; for 
the muscles, when in action, acquire vigour and tense- 
ness, and from soft become hard, prominent, and 
thickened : in the same manner the heart. 

We are therefore authorized to conclude that the 
heart, at the moment of its action, is at once con- 
stricted on all sides, rendered thicker in. its parietes and 
smaller in its ventricles, and so made apt to project or 
expel_its charge of blood. This, indeed, is made 
sufficiently manifest by the fourth observation preceding, 
in which we have seen that the heart, by squeezing out 
the blood it contains becomes paler, and then when it 
sinks into repose and the ventricle is filled anew with 
blood, that the deeper crimson colour returns. But no 
one need remain in doubt of the fact, for if the ventricle 
be pierced the blood will be seen to be forcibly pro- 
jected outwards upon each motion or pulsation when 
the heart is tense. 

These things, therefore, happen together or at the 
same instant : the tension of the heart, the pulse of its 

26 Motion of the 

apex, which is felt externally by its striking against the 
chest, the thickening of its parietes, and the forcible 
expulsion of the blood it contains by the constriction of 
its ventricles. 

Hence the very opposite of the opinions commonly 
received, appears to be true ; inasmuch as it is generally 
believed that when the heart strikes the breast and the 
pulse is felt without, the heart is dilated in its ventricles 
and is filled with blood ; but the contrary of this is the 
fact, arTd"fhe heart, when it contracts [and the shock is 
given], is emptied. Whence the motion which is 
generally regarded as the diastole of the heart, is in 
truth its systole. And in like manner the intrinsic 
motion of the heart is not the diastole but the systole ; 
neither is it in the diastole that the heart grows firm 
and tense, but in the systole, for then only, when tense, 
is it moved and made vigorous. 

Neither is it by any means to be allowed that the 
heart only moves in the line of its straight fibres, 
although the great Vesalius, giving this notion counten- 
ance, quotes a bundle of osiers bound into a pyramidal 
heap in illustration; meaning, that as the apex is ap- 
proached to the base, so are the sides made to bulge 
out in the fashion of arches, the cavities to dilate, the 
ventricles to acquire the form of a cupping-glass and so 
to suck in the blood. But the true effect of every one 
of its fibres is to constringe the hear fat fKe~"5irme time 
that they render it tense ; and this rather with the effect 
of thickening and amplifying the walls and substance of 
the organ than enlarging its ventricles. And, again, as 
the fibres run from the apex to the base, and draw the 
apex towards the base, they do not tend to make the 
walls of the heart bulge out in circles, but rather 
the contrary ; inasmuch as every fibre that is circularly 
disposed, tends to become straight when it contracts ; 
and is distended laterally and thickened, as in the case 
of muscular fibres in general, when they contract, that is, 
when they are shortened longitudinally, as we see them 

Heart and Blood 27 

in the bellies of the muscles of the bod) at large. To 

all this, let it be added, that not only are the ventricles 
iraeted in virtue of the direction and condensation 
of their walls, but farther, that those fibres, or hands, 
Btyled nerves by Aristotle, which are so CUOUS in 

the ventricles of the larger animals, and contain all the 
straight fibres, (the parietes of the heart containing only 
circular ones,) when they contract simultaneously, by 
an admirable adjustment all the internal surfaces are 
drawn together, as if with cords, and so is the charge of 
blood expelled with force. 

Neither is it true, as vulgarly believed, that the heart 
by any dilatation or motion of its own has the power of 
drawing the blood into the ventricles; for when it acts 
and becomes tense, the blood is expelled ; when it 
relaxes and sinks together it receives the blood in the 
manner and wise which will by and by be explained. 



In connection with the motions of the heart these 
things are further to be observed having reference to 
the motions and pulses of the arteries : 

i. At the moment the heart contracts, and when the 
breast is struck, when in short the organ is in its state 
of systole, the arteries are dilated, yield a pulse, and 
are in the state of diastole. In like manner, when the 
right ventricle contracts and propels its charge of blood, 
the arterial vein [the pulmonary artery] is distended at 
the same time with the other arteries of the body. 

2. When the left ventricle ceases to act, to contract, 
to pulsate, the pulse in the arteries also ceases ; further, 
when this ventricle contracts languidly, the pulse in the 
arteries is scarcely perceptible. In like manner, the 
pulse in the right ventricle failing, the pulse in the vena 
arteriosa [pulmonary artery] ceases also. 

3. Further, when an artery is divided or punctured, 
the blood is seen to be forcibly propelled from the 
wound at the moment the left ventricle contracts ; and, 
again, when the pulmonary artery is wounded, the blood 
will be seen spouting forth with violence at the instant 
when the right ventricle contracts. 

So also in fishes, if the vessel which leads from the 
heart to the gills be divided, at the moment when 
the heart becomes tense and contracted, at the same 
moment does the blood flow with force from the 
divided vessel. 


Motion of the Heart and Blood 29 

In the same way, finally, when we see the blood in 
arteriotomy projected now to a greater, now to a less 

distance, and that the greater jet corresponds to the 
diastole of the artery and to the time when the heart 
contracts and strikes the ribs, and is in its state of 
systole, we understand that the blood is expelled by 
the same movement. 

From these facts it is manifest, in opposition to 
commonly received opinions, that the diastole of the 
arteries corresponds with the time of the heart's systole ; 
and that the arteries are filled and distended by the 
blood forced into them by the contraction of the 
ventricles j the arteries, therefore, are distended, be- 
cause they are filled like sacs or bladders, and are not 
filled because they expand like bellows. It is in virtue 
of one and the same cause, therefore, that all the 
arteries of the body pulsate, viz. the contraction of the 
left ventricle ; in the same way as the pulmonary artery 
pulsates by the contraction of the right ventricle. 

Finally, that the pulses of the arteries are due to 
the impulses of the blood from the left ventricle, 
may be illustrated by blowing into a glove, when the 
whole of the fingers will be found to become distended 
at one and the same time, and in their tension to 
bear some resemblance to the pulse. For in the 
ratio of the tension is the pulse of the heart, fuller, 
stronger, more frequent as that acts more vigorously, 
still preserving the rhythm and volume and order of 
the heart's contractions. Nor is it to be expected that 
because of the_ motion of the b loods-tile, time at wh ich 
the conira ctinn nf the hr^r t ra kes phrp, nnri th at at 
which the pulse_in_an artery (especially a distant one) 
is felt, shall be othenme-tha»-s4mulu«eous : it is here 
the same as in- blowi ng- up ,1 g love n r b lfl(ld pr ; f nr in a 
pl enum (as in a drum, a long piece of timber, &c.) the 
stroke and the matknuQecur at both extremities at the 
same time. Aristotle, 1 too, has said, " the blood of all 

1 De Animal, iii, cap. 9. 

30 Motion of the Heart and Blood 

animals palpitates within their veins, (meaning the 
arteries,) and by the pulse is sent everywhere simul- 
taneously." And further, 1 " thus^diL_ajlthe veins 
pulsate together and by successive strokes, because 
they all depend upon the heart ; and, as it is always in 
motion, so are they likewise always moving together, 
but by successive movements." It is well to observe 
with Galen, in this place, that the old philosophers 
called the arteries veins. 

I happened upon one occasion to have a particular 
case under my care, which plainly satisfied me of this 
truth : A certain person was affected with a large 
pulsating tumour on the right side of the neck, called 
an aneurism, just at that part where the artery descends 
into the axilla, produced by an erosion of the artery 
itself, and daily increasing in size; this tumour was 
visibly distended as it received the charge of blood 
brought to it by the artery, with each stroke of the 
heart : the connexion of parts was obvious when the 
body of the patient came to be opened after his death. 
The pulse in the corresponding arm was small, in con- 
sequence of the greater portion of the blood being 
diverted into the tumour and so intercepted. 

Whence it appears that wherever the motion of the 
blood through the arteries is impeded, whether it be by 
compression or infarction, or interception, there do the 
remote divisions of the arteries beat less forcibly, seeing 
that the pulse of the arteries is nothing more than the 
impulse or shock of the blood in these vessels. 

' De Respirat. cap. 20. 



Besides the motions already spoken of, we have still 
to consider those that appertain to the auricles. 

Casper Bauhin and John Riolan, 1 most learned men 
and skilful anatomists, inform us from their observations, 
that if we carefully watch the movements of the heart 
in the vivisection of an animal, we shall perceive four 
motions distinct in time and in place, two of which are 
proper to the auricles, two to the ventricles. With all 
deference to such authority I say, that there are four 
motions distinct in point of place, but not of time ; for 
the two auricles move together, and so also do the two 
ventricles, in such wise that though the places be four, 
the times are only two. And this occurs in the fol- 
lowing manner : 

There are, as it were, two motions going on together : 
one of the auricles, another of the ventricles ; these by 
no means taking place simultaneously, but the motion 
of theauricles preced ing, that of the heaftSts ttlf fol- 
lowing jjfoe motion ap pearing to begin from the auricles 
and tn extend to th ventricles. When all things are be- 
coming lan_;;;iJ, and' the heart is dying, as also in fishes 
and the colder blooded animals, there is a short pause be- 
tween these two motions, so that the heart aroused, as it 
were, appears to respond to the motion, now more quickly, 
now more tardily ; and at length, and when near to 

> Bauhin, lib. ii, cap. 21. Riolan, lib. viii, cap. t. 

32 Motion of the 

death, it ceases to respond by its proper motion, but 
seems, as it were, to nod the head, and is so obscurely 
moved that it appears rather to give signs of motion to 
the pulsating auricle, than actually to move. The heart, 
therefore, ceases to pulsate sooner than the auricles, 
so that the auricles have been said to outlive it, the 
left ventricle ceasing to pulsate first of all ; then its 
auricle, next the right ventricle ; and, finally, all the 
other parts being at rest and dead, as Galen long since 
observed, the right auricle still continues to beat ; life, 
therefore, appears to linger longest in the right auricle. 
Whilst the heart is gradually dying, it is sometimes 
seen to reply, after two or three contractions of the 
auricles, roused as it were to action, and making a 
single pulsation, slowly, unwillingly, and with an effort. 
But this especially is to be noted, that after the 
heart has ceased to beat, the auricles however still 
contracting, a finger placed upon the ventricles per- 
ceives the several pulsations of the auricles, precisely 
in the same way and for the same reason, as we have 
said, that the pulses of the ventricles are felt in the 
arteries, to wit, the distension produced by the jet of 
blood. And if at this time, the auricles alone pulsating, 
the point of the heart be cut off with a pair of scissors, 
you will perceive the blood flowing out" upon each 
contraction of the auricles. Whence it is manifest 
how the blood enters the ventricles, not by any attrac- 
tion or dilatation of the heart, but thrown into them by 
/ the pulses of the auricles. 

And here I would observe, that whenever I speak 
of pulsations as occurring in the auricles or ventricles, 
I mean contractions : first the auricles contract, and 
then and subsequently the heart itself contracts. When 
the auricles contract they are seen to become whiter, 
especially where they contain but little blood ; but 
they are filled as magazines or reservoirs of the blood, 
which is tending spontaneously and, by the motion 
of the veins, under pressure towards the centre; the 

Heart and Rlood 33 

whiteness indicated is most conspicuous towards the 
extremities or edges of the auricles at the time o f their 

In fishes and frogs, and other animals which ha%-e 
hearts with but a single ventricle, and for an auricle 
have a kind of bladder much distended with blood, at 
the base of the organ, you may very plainly perceive 
this bladder contracting first, and the contraction of 
the heart or ventricle following afterwards. 

But I think it riirht to describe what I have observed 
of an opposite character : the heart of an eel, of several 
fishes, and even of some [of the higher] animals taken 
out of the body, beats without auricles ; nay, if it be 
cut in pieces the several parts may still be seen 
contracting and relaxing ; so that in these creatures the 
. of the heart may be seen pulsating, palpitating, 
after the cessation of all motion in the auricle. But is 
not this perchance peculiar to animals more tenacious 
of life, whose radical moisture is more glutinous, or 
fat and sluggish, and less readily soluble? The same 
faculty indeed appears in the flesh of eels, generally, 
which even when skinned and embowelled, and cut into 
pieces, are still seen to move. 

Experimenting with a pigeon upon one occasion, 
after the heart had wholly ceased to pulsate, and the 
auricles too had become motionless, 1 kept my finger 
wetted with saliva and warm for a short time upon the 
heart, and observed, that under the influence of this 
fomentation it recovered new strength and life, so that 
both ventricles and auricles pulsated, contracting and 
relaxing alternately, recalled as it were from death to 

JJesides this, however, I have occasionally observed, 
after the heart and even its right auricle had ceased 
pulsating, — when it was in articulo mortis in short, — 
that an obscure motion, an undulation or palpitation, 
remained in the blood itself, which was contained in 
the right auricle, this being apparent so long as it was 
e 2(5z 

34 Motion of the 

imbued with heat and spirit. And indeed a circum- 
stance of the same kind is extremely manifest in the 
course of the generation of animals, as may be seen in 
the course of the first seven days of the incubation 
of the chick : A drop of blood makes its appearance 
which palpitates, as Aristotle had already observed ; 
from this, when the growth is further advanced and 
the chick is fashioned, the auricles of the heart are 
formed, which pulsating henceforth give constant signs 
of life. When at length, and after the lapse of a few 
days, the outline of the body begins to be distinguished, 
then is the ventricular part of the heart also produced ; 
but it continues for a time white and apparently blood- 
less, like the rest of the animal ; neither does it pulsate 
or give signs of motion. I have seen a similar condition 
of the heart in the human foetus about the beginning 
of the third month, the heart being then whitish and 
bloodless, although its auricles contained a considerable 
quantity of purple blood. In the same way in the egg, 
when the chick was formed and had increased in size, 
the heart too increased and acquired ventricles, which 
then began to receive and to transmit blood. 

And this leads me to remark, that he who inquires 
very particularly into this matter will not conclude that 
the heart, as a whole, is the primum vivens, ultimum 
moriens — the first part to live, the last to die, but 
rather its auricles, or the part which corresponds to the 
auricles in serpents, fishes, &c, which both lives before 
the heart 1 and dies after it. 

Nay, has, not the blood itself or spirit an obscure 
palpitation inherent in it, which it has even appeared 
to me to retain after death ? and it seems very ques- 
tionable whether or not we are to say that life begins 
with the palpitation or beating of the heart. The 
seminal fluid of all animals — the prolific spirit, as 
Aristotle observed, leaves their body with a bound 

1 [The reader will observe that Harvey, when he speaks of the heart, 
always means the ventricles or ventricular portion of the organ.] 

Heart and Blood 33 

and like a living thing ; and nature in death, as 
• (tie 1 further remarks, retracing her steps, reverts 
to whence she had set out, returns at the end of her 
course to the goal whence she had started ; and as 
animal generation proceeds from that which is not 
animal, entity from non-entity, so, by a retrograde 
course, entity, by corruption, is resolved into non-entity ; 
mce that in animals, which was last created, fails 
first : and that which was first, fails last. 

I have also observed, that alm ost all. animals have 
trujvjjjieart, not the Li;. .tares only, ancTthose 

that have red blo od, but the smaller, and [seemingly] 
5 also, such as slugs, snails, scallops, 
shrimps, crabs, crayfish, and many others ; nay, even 
in wasps, hornets, and flies, I have, with the aid of a 
j ni fying glas s^juad at the upper part of what is called 
the tailTboth seen the heart pulsating myself, and shown 
it to many others. 

But in the exsanguine tribes iheLheart pulsates slug- 
glishly and delibe r ately, contracting slowly as in animals 
that are moribund, a fact that may readily be seen in 
th e sn ail, whose heart will be found at the bottom of 
that orifice in the right side of the body which is seen 
to be opened and shut in the course of respiration, and 
whence saliva is discharged, the incision being made 
in the upper aspect of the body, near the part which 
corresponds to the liver. 

This, however, is to be observed : that in winter and 
the colder season, exsanguine animals, such as the snail, 
show no pulsations ; they seem rather to live after the 
manner of vegetables, or of those other productions 
which are therefore designated plant-animals. 

It is also to be noted that aU animals which have a 
heart , ha ve also auric les, or something analogous to 
auricles ; and further, that wherever the heart has a 
double ventricle there are always two auricles present, 
but not otherwise. If you turn to the production of 

' De Motu Animal, cap. 8. 

36 Motion of the Heart and Blood 

the chick in ovo, however, you will find at first no more 
than a vesicle or auricle, or pulsating drop of blood ; it 
is only by and by, when the development has made 
some progress, that the heart is fashioned : even so in 
certain animals not destined to attain to the highest 
perfection in their organization, such as bees, wasps, 
snails, shrimps, crayfish, &c, we only find a certain 
pulsating vesicle, like a sort of red or white palpitating 
point, as the beginning or principle of their life. 

We have a small shrimp in these countries, which 
is taken in the Thames and in the sea, the whole of 
whose body is transparent ; this creature, placed in a 
little water, has frequently afforded myself and particular 
friends an opportunity of observing the motions of the 
heart with the greatest distinctness, the external parts 
of the body presenting no obstacle to our view, but 
the heart being perceived as though it had been seen 
through a window. 

1 have also observed the first rudiments of the chick 
in the course of the fourth or fifth day of the incubation, 
in the guise of a little cloud, the shell having been 
removed and the egg immersed in clear tepid water. 
In the midst of the cloudlet in question there was a 
bloody point so small that it disappeared during the 
contraction and escaped the sight, but in the relaxation 
it reappeared again, red and like the point of a pin ; so 
that betwixt the visible and invisible, betwixt being and 
not being, as it were, it gave by its pulses a kind of 
representation of the commencement of life. 1 

' [At the period Harvey indicates, a rudimentary auricle and ventricle 
exist, but are to transparent that unless with certain precautions their 
panetes cannot be seen. The filling and emptying of them, therefore, 
give the appearance of a speck of blood alternately appearing and 




From these and other observations of the like kind, 
I am persuaded it will be found that the motion of 
the heart is as follows : 

First of all, the auricle contracts, and in the course 
of its contraction throws the blood, (which it contains 
in ample quantity as the head of the veins, the store- 
house, and cistern of the blood,) into the ventricle, 
which, being filled, the heart raises itself straightway, 
makes all its fibres tense, contracts the ventricles, and 
performs a beat, by which beat it immediately sends 
the blood supplied to it by the auricle into the arteries ; 
the right ventricle sending its charge into the lungs 
by the vessel which is called vena arteriosa, but which, 
in structure and function, and all things else, is an 
artery; the left ventricle sending its charge into the 
aorta, and through this by the arteries to the body 
at large. 

These two motions, one of the ventricles, another 
of the auricles, take place consecutively, but in such 
a manner that there is a kind of harmony or rhythm 
preserved between them, the two concurring in such 
wise that but one motion is apparent, especially in the 
warmer blooded animals, in which the movements in 
question are rapid. Nor is this for any other reason 
than it is in a piece of machinery, in which, though 
one wheel gives motion to another, yet all the wheels 
seem to move simultaneously ; or in that mechanical 
contrivance which is adapted to firearms, where the 



Motion of the 

trigger being touched, down comes the flint, strikes 
against the steel, elicits a spark, which falling among 
the powder, it is ignited, upon which the flame extends, 
enters the barrel, causes the explosion, propels the ball, 
and the mark is attained — all of which incidents, by 
reason of the celerity with which they happen, seem 
to take place in the twinkling of an eye. So also in 
deglutition : by the elevation of the root of the tongue, 
and the compression of the mouth, the food or drink 
is pushed into the fauces, the larynx is closed by its 
own muscles, and the epiglottis, whilst the pharynx, 
raised and opened by its muscles no otherwise than 
is a sac that is to be filled, is lifted up, and its mouth 
dilated ; upon which, the mouthful being received, it 
is forced downwards by the transverse muscles, and 
then carried farther by the longitudinal ones. Yet are 
all these motions, though executed by different and 
distinct organs, performed harmoniously, and in such 
order, that they seem to constitute but a single motion 
and act, which we call deglutition. 

Even so does it come to pass with the motions and 
action of the heart, which constitute a kind of deglu- 
tition, a transfusion of the blood from the veins to the 
arteries. And if any one, bearing these things in mind, 
will carefully watch the motions of the heart in the 
body of a living animal, he will perceive not only all 
the particulars I have mentioned, viz. the heart be- 
coming erect, and making one continuous motion with 
its auricles ; but farther, a certain obscure undulation 
and lateral inclination in the direction of the axis of 
the right ventricle, [the organ] twisting itself slightly 
in performing its work. And indeed every one may 
see, when a horse drinks, that the water is drawn in 
and transmitted to the stomach at each movement of 
the throat, the motion being accompanied with a 
sound, and yielding a pulse both to the ear and the 
touch ; in the same way it is with each motion of 
the heart, when there is the delivery of a quantity 

Heart and Blood 39 

Of blood from the veins to the arteries, that a pulse 
takes place, and can he heard within the chest. 

The motion of the heart, then, is entirely of this 
description, and the one action of the heart is the 
transmission of the blood and its distribution, by 
means of the arteries, to the very extremities of the 
body ; so that the pulse which we feel in the arteries 
is nothing more than the impulse of the blood derived 
from the heart. 

Whether or not the heart, besides propelling the 
blood, giving it motion locally, and distributing it to 
the body, adds anything else to it, — heat, spirit, per- 
fection, — must be inquired into by and by, and decided 
upon other grounds. So much may suffice at this 
time, when it is shown that by the action of the heart 
the blood is transfused through the ventricles from the 
veins to the arteries, and distributed by them to all 
parts of the body. 

So much, indeed, is admitted by all [physiologists], 
both from the structure of the heart and the arrange- 
ment and action of its valves. But still they are like 
persons purblind or groping about in the dark ; and 
then they give utterence to diverse, contradictory, and 
incoherent sentiments, delivering many things upon 
conjecture, as we have already had occasion to remark. 

The grand cause of hesitation and error in this 
subject appears to me to have been the intimate con- 
nection betweenjt he heart and the lungs. When men 
saw both_J±Le^£iia-a#eriosa [or pulmonary artery] and 
the arter ire ve nosse [or pulmonary veins] losing them- 
selves in the lungs, of course it beca me a p uzzle to 
them TTfF"know how or by wMt means th e right 
ventricle should distribute the blood to the body, or 
the left draw it from the venae cava;. This fact is 
born witness to by Galen, whose words, when writing 
against Erasistratus in regard to the origin and use of the 
veins and the coction of the blood, are the following : l 

1 De Placitis Hippocratis et Platonis, vi. 

^o Motion of the 

" You will reply," he says, " that the effect is so ; that 
the blood is prepared in the liver, and is thence 
transferred to the heart to receive its proper form and 
last perfection; a statement which does not appear 
devoid of reason ; for no great and perfect work is 
ever accomplished at a single effort, or receives its final 
polish from one instrument. But if this be actually so, 
then show us another vessel which draws the absolutely 
perfect blood from the heart, and distributes it as the 
arteries do the spirits over the whole body." Here 
then is a reasonable opinion not allowed, because, 
forsooth, besides not seeing the true means of transit, 
he could not discover the vessel which should transmit 
the blood from the heart to the body at large ! 

But had any one been there in behalf of Erasistratus, 
and of that opinion which we now espouse, and which 
Galen himself acknowledges in other respects consonant 
with reason, to have pointed to the aorta as the vessel 
which distributes the blood from the heart to the rest 
of the body, I wonder what would have been the 
answer of that most ingenious and learned man ? Had 
he said that the artery transmits spirits and not blood, 
he would indeed sufficiently have answered Erasistratus, 
who imagined that the arteries contained nothing but 
spirits ; but then he would have contradicted himself, 
and given a foul denial to that for which he had keenly 
contended in his writings against this very Erasistratus, 
to wit, that blood in substance is contained in the 
arteries, and not spirits ; a fact which he demonstrated 
not only by many powerful arguments, but by ex- 

But if the divine Galen will here allow, as in other 
places he does, " that all the arteries of the body arise 
from the great artery, and that this takes its origin 
from the heart ; that all these vessels naturally contain 
and carry blood ; that the three semilunar valves 
situated at the orifice of the aorta prevent the return 
of the blood into the heart, and that nature never 

Heart and Blood 41 

connected them with this, the most noble viscus of the 
body, unless for some most important end;" if, I say, tiiis 
father of physic admits all these things, — and I quote 
his own words, — I do not see how he can deny that 
the great artery is the very vessel to carry the blood, 
when it has attained its highest term of perfection, 
from the heait for distribution to all parts of the body. 
Or would he perchance still hesitate, like all who have 
come after him, even to the present hour, because he 
did not perceive the route by which the blood was 
transferred from the veins to the arteries, in consequence, 
as I have already s'aTd, of the intimate connexion be- 
tween the heart and the lungs ? And that this difficulty 
puzzled anatomists not a little, when in their dissections 
they found the pulmonary artery and left ventricle full 
of thick, black, and clotted blood, plainly appears, 
when they felt themselves compelled to affirm that the 
blood made its way from the right to the left ventricle 
by sweating through the septum of the heart. But 
this I fancy I have already refuted. A new pathway 
for the blood must therefore .be prepared and thrown 
open, and being once exposed, no further difficulty 
will, I believe, be experienced by any one in admitting 
what I have already proposed in regard to the pulse 
of the heart and arteries, viz. the passage of the blood 
from the veins to the arteries, and its distribution to 
the whole of the body by means of these vessels. 



Since the intimate connexion of the heart with the 
lungs, which is apparent in the human subject, has 
been the probable cause of the errors that have been 
committed on this point, they plainly do amiss who, 
pretending to speak of the parts of animals generally, 
as anatomists for the most part do, confine their re- 
searches to the human body alone, and that when it 
is dead. They obviously act no otherwise than he 
who, having studied the forms of a single common- 
wealth, should set about the composition of a general 
system of polity ; or who, having taken cognizance of 
the nature of a single field, should imagine that he 
had mastered the science of agriculture ; or who, upon 
the ground of one particular proposition, should pro- 
ceed to draw general conclusions. 

Had anatomists only been as conversant with the 
dissection of the lower animals as they are with that of 
the human body, the matters that have hitherto kept 
them in a perplexity of doubt would, in my opinion, 
have met them freed from every kind of difficulty. 

And, first, in fishes, in which the heart consists of 
but a single ventricle, they having no lungs, the thing 
is sufficiently manifest. Here the sac, which is situ- 
ated at the base of the heart, and is the part analogous 
to the auricle in man, plainly throws the blood into the 
heart, and the heart, in its turn, conspicuously transmits 


Motion of the Heart and Blood 43 

it by a pipe Of artery, ur vessel analogous to an artery ; 
these are facts winch are confirmed by simple ocular 
inspection, as well as by a division of the vessel, when 
!>lood is seen to be projected by each pulsation of 
the heart. 

The same thing is also not difficult of demonstration 
in those animals that have either no more, or, as it 
were, no more than a single ventricle to the heart, such 
as toads, frogs, serpents, and lizards, which, althoi 
they have lungs in a certain senSeTTls they have a voice, 
(and I have many observations by me on the admirable 
structure of the lungs of these animals, and matters 
appertaining, which, however, I cannot introduce in 
this place,) still their anatomy plainly shows that the 
':■; i l- transferred in them from the veins to the 
arteries in the same manner as in higher animals, 
vi . b) the action of the heart: the way, in fact, is 
nt, open, manifest ; there is no difficulty, no room 
for hesitating about it ; for in them the matter stands 
precisely as it would in man, were the septum of his 
heart perforated or removed, or one ventricle made out 
of two ; and this being the case, I imagine that no one 
will doubt as to the way by which the blood may pass 
from the veins into the arteries. 

But as there are actually more animals which have 
no lungs than there are which be furnished with them, 
and in like manner a greater number which have only- 
one ventricle than there are which have two, it is open to 
us to conclude, judging from the mass or multitude of 
living creatures, that for the major part, and generally, 
there is an open way by which the blood is transmitted 
from the veins through the sinuses or cavities of the 
heart into the arteries. 

I have, however, cogitating with myself, seen further, 
that the same thing obtained most obviously in the 
embryos of those animals that have lungs ; for in the 
fcetus the four vessels belonging to the heart, viz. 
the vena cava, the vena arteriosa or pulmonary artery, 

44 Motion of the 

the arteria venalis or pulmonary vein, and the arteria 
magna or aorta, are all connected otherwise than in the 
adult ; a fact sufficiently known to every anatomist. 
The first contact and union of the vena cava with the 
arteria venosa or pulmonary veins, which occurs before 
the cava opens properly into the right ventricle of the 
heart, or gives off the coronary vein, a little above its 
escape from the liver, is by a lateral anastomosis ; this 
is an ample foramen, of an oval form, communicating 
between the cava and the arteria venosa, or pulmonary 
vein, so that the blood is free to flow in the greatest 
abundance by that foramen from the vena cava into the 
arteria venosa or pulmonary vein, and left auricle, and 
from thence into the left ventricle ; and farther, in this 
foramen ovale, from that part which regards the arteria 
venosa, or pulmonary vein, there is a thin tough 
membrane, larger than the opening, extended like an 
operculum or cover ; this membrane in the adult 
blocking up the foramen, and adhering on all sides, 
finally closes it up, and almost obliterates every trace 
of it. This membrane, however, is so contrived in the 
foetus, that falling loosely upon itself, it permits a ready 
access to the lungs and heart, yielding a passage to the 
blood which is streaming from the cava, and hindering 
the tide at the same time from flowing back into that 
vein. All things, in short, permit us to believe that in 
the embryo the blood must constantly pass by this 
foramen from the vena cava into the arteria venosa, or 
pulmonary vein, and from thence into the left auricle 
of the heart ; and having once entered there, it can 
never regurgitate. 

Another union is that by the vena arteriosa, or 
pulmonary artery, and is effected when that vessel 
divides into two branches after its escape from the 
right ventricle of the heart. It is as if to the two 
trunks already mentioned a third was superadded, a 
kind of arterial canal, carried obliquely from the vena 
arteriosa, or pulmonary artery, to perforate and termi- 

I [eart and Blood 45 

nate in the arteria magna or aorta. In the embryo, 

consequently, there arc, as it were, two aortas, or two 
roots of the arteria magna, springing from the heart. 
This canalis arteriosus shrinks gradually after birth, 
and is at length and finally almost entirely withered, 
and removed, like the umbilical vessels. 

The canalis arteriosus contains no membrane or 
valve to direct or impede the flow of the blood in this 
or in that direction : for at the root of the vena 
arteriosa, or pulmonary artery, of which the canalis 
arteriosus is the continuation in the foetus, there are 
three sigmoid or semilunar valves, which open from 
within outwards, and oppose no obstacle to the blood 
flowing in this direction or from the right ventricle into 
the pulmonary artery and aorta ; but they prevent all 
regurgitation from the aorta or pulmonic vessels back 
upon the right ventricle ; closing with perfect accuracy, 
they oppose an effectual obstacle to everything of the 
kind in the embryo. So that there is also reason to 
believe that when the heart contracts, the blood is 
regularly propelled by the canal or passage indicated 
from the right ventricle into the aorta. 

What is commonly said in regard to these two great 
communications, to wit,. that they exist for the nutrition 
of the lungs, is both improbable and inconsistent ; 
seeing that in the adult they are closed up, abolished, 
and consolidated, although the lungs, by reason of their 
heat and motion, must then be presumed to require 
a larger supply of nourishment. The same may be said 
in regard to the assertion that the heart in the embryo 
does not pulsate^ that it neither acts nor moves, so 
that nature was forced to make these communications 
for the nutrition of the lungs. This is plainly false; 
for simple inspection of the inmhnr^rl pw anH of 
embryos just taken out of the uieras, suows that the 
o« flrt mov e o -precls'ely jn them as in adults, and that 
nature feels no such necessity. I have myself re- 
peatedly seen these motions, and Aristotle is likewise 

4 6 

Motion of the 

witness of their reality. "The pulse," he observes, 
" inheres in the very constitution of the heart, and 
appears from the beginning, as is learned both from 
the dissection of living animals, and the formation of the 
chick in the egg." 1 But we further observe, that 
the passages in question are not only pervious up to 
the period of birth in man, as well as in other animals, 
as anatomists in general have described them, but for 
several months subsequently, in some indeed for several 
years, not to say for the whole course of life ; as, for 
example, in the goose, snipe, and various birds, and 
many of the smaller animals. And this circumstance 
it was, perhaps, that imposed upon Botallus, who 
thought he had discovered a new passage for the 
blood from the vena cava into the left ventricle of 
the heart ; and I own that when I met with the same 
arrangement in one of the larger members of the 
mouse family, in the adult state, I was myself at first 
led to something of a like conclusion. 

From this it will be understood that in the human 
embryo, and in the embryos of animals in which the 
communications are not closed, the same thing happens, 
namely, that the heart by its motion propels the blood 
by obvious and open passages from the vena cava into 
the aorta through the cavities of both the ventricles ; 
the right one receiving the blood from the auricle, and 
propelling it by the vena arteriosa, or pulmonary artery, 
and its continuation, named the ductus arteriosus, into 
the aorta ; the left, in like manner, charged by the 
contraction of its auricle, which has received its supply 
through the foramen ovale from the vena cava, con- 
tracting, and projecting the blood through the root of 
the aorta into the trunk of that vessel. 

In embryos, consequently, whilst the lungs are yet in 
a state of inaction, performing no function, subject to 
no motion any more than if they had not been present, 
nature uses the two ventricles of the heart as if they 

1 Lib. de Spiritu, cap. v. 

Heart and Blood 47 

formed but one, for the transmission o( the blood. 
The condition of the embryo.-, of those animals which 
have lungs, whilst these organs are yet in abeyance and 
not employed, is the same as that of those animals 
which have no lungs. 

- 1 clearly, theref ire, does it appear in the case of 
the foetus, viz. that the heart by its action transfers the 
blood from the vena cava into the aorta, and that by a 
route as obvious and open, as if in the adult the two 
ventricles were made to communicate by the removal 
of their septum. Since, then, we find that in the 
greater number of animals, in all, indeed, at a certain 
period of their existence, the channels for the trans- 
mission of the blood through the heart are so con- 
spicuous, we have still to inquire wherefore in some 
creatures — those, namely, that have warm blood, and 
that have attained to the adult age, man among the 
number — we should not conclude that the same thing 
is accomplished through the substance of the lungs, 
which in the embryo, and at a time when the function 
of these organs is in abeyance, nature effects by the 
direct passages described, and which, indeed, she 
seems compelled to adopt through want of a passage 
by the lun^s ; or wherefore it should be better (for 
nature always does that which is best) that she should 
close up the various open routes which she had for- 
merly made use of in the embryo and foetus, and still 
uses in all other animals ; not only opening up no new- 
apparent channels for the passage of the blood, there- 
fore, but even entirely shutting up those which formerly- 

And now the discussion is brought to this point, 
that they who inquire into the ways by which the 
blood reaches the left ventricle of the heart and pul- 
monary veins from the vena cava, will pursue the 
wisest course if they seek by dissection to discover the 
causes why in the larger and more perfect animals of 
mature age, nature has rather chosen to make the 

48 Motion of the Heart and Blood 

blood percolate the parenchyma of the lungs, than as 
in other instances chosen a direct and obvious course 
— for I assume that no other path or mode of transit 
can be entertained. It must be either because the 
larger and more perfect animals are warmer, and when 
adult their heat greater — ignited, as I might say, and 
requiring to be damped or mitigated ; therefore it may 
be that the blood is sent through the lungs, that it may 
be tempered by the air that is inspired, and prevented 
from boiling up, and so becoming extinguished, or 
something else of the sort. But to determine these 
matters, and explain them satisfactorily, were to enter 
on a speculation in regard to the office of the lungs and 
the ends for which they exist; and upon such a subject, 
as well as upon what pertains to eventilation, to the 
necessity and use of the air, &c, as also to the variety 
and diversity of organs that exist in the bodies of 
animals in connexion with these matters, although I 
have made a vast number of observations, still, lest 
I should be held as wandering too wide of my present 
purpose, which is the use and motion of the heart, and 
be charged with speaking of things beside the question, 
and rather complicating and quitting than illustrating it, 
I shall leave such topics till I can more conveniently 
set them forth in a treatise apart. And now, returning 
to my immediate subject, I go on with what yet 
remains for demonstration, viz. that in the more 
perfect and warmer adult animals, and man, the blood 
passes from the right ventricle of the heart by the vena 
arteriosa, or pulmonary artery, into the lungs, and 
thence by the arteriae venosse, or pulmonary veins, into 
the left auricle, and thence into the left ventricle of the 
heart. And, first, I shall show that this may be so, 
and then I shall prove that it is so in fact. 



That this is possible, and that there is nothing to 
prevent it from being so, appears when we reflect on 
the way in which water percolating the earth produces 
springs and rivulets, or when we speculate on the 
means by which the sweat passes through the skin, • 
or the urine through the parenchyma of the kidneys. 
It is well known that persons who use the Spa waters, 
or those of La Madonna, in the territories of Padua, or 
others of an acidulous or vitriolated nature, or who 
simply swallow drinks by the gallon, pass all off again 
within an hour or two by urine. Such a quantity of 
liquid must take some short time in the concoction : 
it must pass through the. liver ; (it is allowed by all 
that the juices of the food we consume pass twice 
through this organ in the course of the day ;) it must 
flow through the veins, through the parenchyma of the 
kidneys, and through the ureters into the bladder. 

To those, therefore, whom I hear denying that the 
blood, aye the whole mass of the blood may pass 
through the substance of the lungs, even as the 
nutritive juices percolate the liver, asserting such a 
proposition to be impossible, and by no means to be 
entertained as credible, I reply, with the poet, that 
they are of that race of men who, when they will, 
assent full readily, and when they will not, by no 
manner of means ; who, when their assent is wanted, 
fear, and when it is not, fear not to give it. 
F * 62 49 

50 Motion of the 

The parenchyma of the liver is extremely dense, 
so is that of the kidney ; the lungs, again, are of a 
much looser texture, and if compared with the kidneys 
are absolutely spongy. In the liver there is no forcing, 
no impelling power ; in the lungs the blood is forced 
on by the pulse of the right ventricle, the necessary 
effect of whose impulse is the distension of the vessels 
and pores of the lungs. And then the lungs, in respira- 
tion, are perpetually rising and falling ; motions, the 
effect of which must needs be to open and shut the 
pores and vessels, precisely as in the case of a sponge, 
and of parts having a spongy structure, when they are 
alternately compressed and again are suffered to expand. 
The liver, on the contrary, remains at rest, and is never 
seen to be dilated and constricted. Lastly, if no one 
denies the possibility of the whole of the ingested 
juices passing through the liver, in man, oxen, and the 
larger animals generally, in order to reach the vena 
cava, and for this reason, that if nourishment is to 
go on, these juices must needs get into the veins, and 
there is no other way but the one indicated, why should 
not the same arguments be held of avail for the passage 
of the blood in adults through the lungs ? Why not, 
with Columbus, that skilful and learned anatomist, 
maintain and believe the like, from the capacity and 
structure of the pulmonary vessels; from the fact of 
the pulmonary veins and ventricle corresponding with 
them, being always found to c^ncain blood, which 
must needs have come from the veins, and by no other 
passage save through the lungs ? Columbus, and we 
also, from what precedes, from dissections, and other 
arguments, conceive the thing to be clear. But as 
there are some who admit nothing unless upon 
authority, let them learn that the truth I am contending 
for can be confirmed from Galen's own words, namely, 
that not only may the blood be transmitted from the 
pulmonary artery into the pulmonary veins, then into 
the left ventricle of the heart, and from thence into the 

Heart and Blood 51 

arteries_of_thebody, hut that this is effected by the 
ce.: pulsation of the heart and the motion of 

the hTnls in breathing. 

There are, as every one knows, three sigmoid or 
semilunar valves situated at the orifice of the pulmonary 
artery, which effectually prevent the blood sent into the 
vessel from returning into the cavity of the heart. 
Now Galen, explaining the uses of these valves, and 
the necessity for them, employs the following lan- 
guage : l "There is everywhere a mutual anastomosis 
and inosculation of the arteries with the veins, and 
they severally transmit both blood and spirit, by certain 
invisible and undoubtedly very narrow passages. Now 
if the mouth of the vena arteriosa, or pulmonary artery, 
had stood in like manner continually open, and nature 
had found no contrivance for closing it when requisite, 
and opening it again, it would have been impossible 
that the blood could ever have passed by the invisible 
and delicate mouths, during the contractions of the 
thorax, into the arteries ; for all things are not alike 
readily attracted or repelled ; but that which is light is 
more readily drawn in, the instrument being dilated, 
and forced out again when it is contracted, than that 
whichjsjieavy ; and in like manner is anything drawn 
more rapidly along an ample conduit, and again driven 
forth, than it is through a narrow tube. But whenihe-- 
thorajc_js__cQrLtracted 3 the pulmonary veins, which are 
in \KtT lungs, being driven inwardly, and powerfully 
compressed on every side, immediately force out some 
of the spirit they contain, and at the same time assume 
a certain portion of blood by those subtile mouths ; 
a thing that could never come to pass were the blood 
at liberty to flow back into the heart through the great 
orifice of the pulmonary artery. But its return through 
this great opening being prevented, when it is com- 
pressed on every side, a certain portion of it distils into 
the pulmonary veins by the minute orifices mentioned. V- 

1 De Usu partium, lib. vi. cap. 10. /\K^~~ ~~^^ /. 


52 Motion of the 

And shortly afterwards, in the very next chapter, he 
says : " The more the thorax contracts, the more it 
strives to force out the blood, the more exactly do 
these membranes (viz. the sigmoid valves) close up the 
mouth of the vessel, and suffer nothing to regurgitate." 
The same fact he has also alluded to in a preceding 
part of the tenth chapter : " Were there, no_ valves, 
a three-fold inconvenience would result^ so that the 
blood would then perform this lengthened course in 
vain ; it would flow inwards during the diastoles of the 
lungs, and fill all their arteries ; but in the systoles, 
in the manner of the tide, it would ever and anon, like 
the Euripus, flow backwards and forwards by the same 
way, with a reciprocating motion, which would nowise 
suit the blood. This, however, may seem a matter of 
little moment ; but if it meantime appear that the 
function of respiration suffer, then I think it would be 
looked upon as no trifle, &c." And, again, and shortly 
afterwards: "And then a third inconvenience, by no 
means to be thought lightly of, would follow, were the 
blood moved backwards during the expirations, had 
not our Maker instituted those supplementary mem- 
branes [the sigmoid valves]." Whence, in the eleventh 
chapter, he concludes : " That they have all a common 
use, (to wit, the valves,) and that it is to prevent 
regurgitation or backward motion ; each, however, 
having a proper function, the one set drawing matters 
from the heart, and preventing their return, the other 
drawing matters into the heart, and preventing their 
escape from it. For nature never intended to distress 
the heart with needless labour, neither to bring aught 
into the organ which it had been better to have kept 
away, nor to take from it again aught which it was 
requisite should be brought. Since, then, there are 
four orifices in all, two in either ventricle, one of these 
induces, the other educes." And again he says : 
"Farther, since there is one vessel, consisting of a 
simple tunic, implanted in the heart, and another, 

Heart and Blood 53 

having a double tunic, extending from it, (Galen is here 
speaking of the right side of the heart, hut I extend his 
observations to the left side also,) a kind of reservoir 
had to be provided, to which both belonging, the blood 
should be drawn in by the one, and sent out by the 

This argument Galen adduces for the transit of the 
blood by the right ventricle from the vena cava into 
the lungs ; but we can use it with still greater propriety, 
merely changing the terms, for the passage of the blood 
from the veins through the heart into the arteries. 
Frum Galen, however, that great man, that father of 
physicians, it clearly appears that ^he blood passes 
through the lungs from the pulmonary artery into the 
minute branches of the pulmonary veins, urged to this 
both by the pulses of the heart and by the motions of 
the lungs and thorax; that the heart, moreover, is 
incessantly receiving and expelling the blood by and 
from its ventricles, as from a magazine or cistern, and 
for this end is furnished with four sets of valves, two 
serving for the induction and two for the eduction of 
the blood, lest, like the Euripus, it should be incom- 
modiously sent hither and thither, or flow back into 
the cavity which it should have quitted, or quit the 
part where its presence was required, and so the heart 
be oppressed with labour in vain, and the office of the 
lungs be interfered with. 1 Finally, J)ur position that 
the blood is continually passing from the right to the 
left ventricle, frum the vena cava into the aorta, through 
the porous structure of the lungs, plainly appears from 
this, that since the blood is incessantly sent from the 
right ventricle into the lungs by the pulmonary artery, 
and in like manner is incessantly drawn from the lungs 
into the left ventricle, as appears from what precedes 
and the position of the valves, it cannot do otherwise 

1 See the Commentary of the learned Hofmann upon the Sixth Book 
of Galen, " De Usn partium," a work which I first saw after I had 
written what precedes. 

54 Motion of the Heart and Blood 

than pass through continuously. And then, as the 
blood is incessantly flowing into the right ventricle of 
the heart, and is continually passed out from the left, 
as appears in like manner, and as is obvious both to 
sense and reason, it is impossible that the blood can 
do otherwise than pass continually from the vena cava 
into the aorta. 

Dissection consequently shows distinctly what takes 
place [in regard to the transit of the blood] in the 
greater number of animals, and indeed in all, up to 
the period of their [fcetal] maturity ; and that the same 
thing occurs in adults is equally certain, both from 
Galen's words, and what has already been said on the 
subject, only that in the former the transit is effected 
by open and obvious passages, in the latter by the 
obscure porosities of the lungs and the minute inoscula- 
tions of vessels. Whence it appears that, although one 
ventricle of the heart, the left to wit, would suffice for 
the distribution of the blood over the body, and its 
eduction from the vena cava, as indeed is done in those 
creatures that have no lungs, nature, nevertheless, when 
she ordained that the same blood should also perco- 
late the lungs, saw herself obliged to add another 
ventricle, the right, the pulse of which should force the 
blood from the vena cava through the lungs into the 
cavity of the left ventricle. In this way, therefore, it 
may be said that the right ventricle is made for the 
sake of the lungs, and for the transmission of the blood 
through them, not for their nutrition ; seeing it were 
unreasonable to suppose that the lungs required any so 
much more copious a supply of nutriment, and that of 
so much purer and more spirituous a kind, as coming 
immediately from the ventricle of the heart, than either 
the brain with its peculiarly pure substance, or the eyes 
with their lustrous and truly admirable structure, or the 
flesh of the heart itself, which is more commodiously 
nourished by the coronary artery. 



Thus far I have spoken of the passage of the blood 
from the veins into the arteries, and of the manner in 
which it is transmitted and distributed by the action of 
the heart; points to which some, moved either by the 
authority of Galen or Columbus, or the reasonings of 
others, will give in their adhesion. But what remains 
to be said upon the quantity and source of the blood 
which thus passes, is of so novel and unheard-of 
character, that I not only fear injury to myself from the 
envy of a few, but I tremble lest I have mankind at 
large for my enemies, so much doth wont and custom, 
that become as another nature, and doctrine once 
sown and that hath struck deep root, and respect for 
antiquity influence all men : Still the die is cast, and 
my trust is in my love of truth, and the candour that 
inheres in cultivated minds. And sooth to say, when 
I surveyed my mass of evidence, whether derived from 
vivisections, and my various reflections on them, or 
from the ventricles of the heart and the vessels that 
enter into and issue from them, the symmetry and size 
of these conduits, — for nature doing nothing in vain, 
would never have given them so large a relative size 
without a purpose, — or from the arrangement and inti- 
mate structure of the valves in particular, and of the 
other parts of the heart in general, with many things 
besides, I frequently and seriously bethought me, and 



Motion of the 

long revolved in my mind, what might be the quantity 
of blood which was transmitted, in how short a time 
its passage might be effected, and the like ; and not 
finding it possible that this could be supplied by the 
juices of the ingested aliment without the veins on 
the one hand becoming drained, and the arteries on the 
other getting ruptured through the excessive charge of 
blood, unless the blood should somehow find its way 
from the arteries into the veins, and so return to the 
right side of the heart ; I began to think whether there 
might not be a a motion, as it were, in a circle. 
Now this I afterwards found to be true ; and I finally 
saw that the blood, forced by the action of the left 
ventricle into the arteries, was distributed to the body 
at large, and its several parts, in the same manner as it 
is sent through the lungs, impelled by the right ventricle 
into the pulmonary artery, and that it then passed 
through the veins and along the vena cava, and so 
round to the left ventricle in the manner already in- 
dicated. Which motion we may be allowed to call 
circular, in the same way as Aristotle says that the air 
and the rain emulate the circular motion of the superior 
bodies ; for the moist earth, warmed by the sun, evapo- 
rates ; the vapours drawn upwards are condensed, and 
descending in the form of rain, moisten the earth 
again ; and by this arrangement are generations of living 
things produced ; and in like manner too are tempests 
and meteors engendered by the circular motion, and by 
the approach and recession of the sun. 

And so, in all likelihood, does it come to pass in the 
body, through the motion of the blood ; the various 
parts are nourished, cherished, quickened by the warmer, 
more perfect, vaporous, spirituous, and, as I may say, 
alimentive blood ; which, on the contrary, in contact 
with these parts becomes cooled, coagulated, and, so 
to speak, effete ; whence it returns to its sovereign the 
heart, as if to its source, or to the inmost home of 
the body, there to recover its state of excellence or 

Heart and Blood 57 

perfection. I [ere it resumes its due fluidity and receives 

an infusion of natural heat — powerful, fervid, a kind of 
treasury of life, and is impregnated with spirits, and it 
might be said with balsam ; and thence it is again dis- 
persed ; and all this depends on the motion and action 
of the heart. 

The heart, consequently, is the beginning of life ; the 
sun of the microcosm, even as the sun in his turn might 
well lie designated the heart of the world; for it is the 
heart by whose virtue and pulse the blood is moved, 
perfected, made apt to nourish, and is preserved from 
corruption and coagulation ; it is the household divinity 
which, discharging its function, nourishes, cherishes, 
quickens the whole body, and is indeed the foundation 
of life, the source of all action. But of these things we 
shall speak more opportunely when we come to specu- 
late upon the final cause of this motion of the heart. 

Hence, since the veins are the conduits and vessels 
that transport the blood, they are of two kinds, the 
cava and the aorta ; and this not by reason of there 
beihg two sides of the body, as Aristotle has it, but 
because of the difference of office ; nor yet, as is com- 
monly said, in consequence of any diversity of structure, 
for in many animals, as I have said, the vein does not 
differ from the artery in the thickness of its tunics, but 
solely in virtue of their several destinies and uses. A 
vein and an artery, both styled vein by the ancients, 
and that not undeservedly, as Galen has remarked, 
because the one, the artery to wit, is the vessel which 
carries the blood from the heart to the body at large, 
the other or vein of the present day bringing it back 
from the general system to the heart ; the former is the 
conduit from, the latter the channel to, the heart; the 
latter contains the cruder, effete blood, rendered unfit 
for nutrition ; the former transmits the digested, perfect, 
peculiarly nutritive fluid. 



But lest any one should say that we give them words 
only, and make mere specious assertions without any 
foundation, and desire to innovate without sufficient 
cause, three points present themselves for confirmation, 
which being stated, I conceive that the truth I contend 
for will follow necessarily, and appear as a thing obvious 
to all. First, — the blood is incessantly transmitted by 
the action of the heart from the vena cava to the 
arteries in such quantity, that it cannot be supplied 
from the ingesta, and in such wise that the whole mass 
must very quickly pass through the organ ; Second, — 
the blood under the influence of the arterial pulse enters 
and is impelled in a continuous, equable, and incessant 
stream through every part and member of the body, in 
much larger quantity than were sufficient for nutrition, 
or than the whole mass of fluids could supply ; Third, — 
the veins in like manner return this blood incessantly 
to the heart from all parts and members of the body. 
These points proved, I conceive it will be manifest 
that the blood circulates, revolves, propelled and then 
returning, from the heart to the extremities, from the 
extremities to the heart, and thus that it performs a 
kind of circular motion. 

Let us assume either arbitrarily or from experiment, 
the quantity of blood which the left ventricle of the 
heart will contain when distended to be, say two ounces, 
three ounces, one ounce and a half — in the dead body 


Motion of the Heart and Blood 59 

I have found it to hold upwards of two ounces. Let 
us assume further, how much less the heart will hold 
in the contracted than in the dilated state ; and how 
much blood it will project into the aorta upon each 
contraction; — and all the world allows that with the 
systole something is always projected, a necessary con- 
sequence demonstrated in the third chapter, and obvious 
from the structure of the valves ; and let us suppose as 
approaching the truth that the fourth, or fifth, or sixth, 
or even but the eighth part of its charge is thrown into 
the artery at each contraction ; this would give either 
half an ounce, or three drachms, or one drachm of 
blood as propelled by the heart at each pulse into 
the aorta ; which quantity, by reason of the valves at 
the root of the vessel, can by no means return into the 
ventricle. Now, in the course of half an hour, the heart 
will have made more than one thousand beats, in some 
as many as two, three, and even four thousand. Multi- 
plying the number of drachms propelled by the number 
of pulses, we shall have either one thousand half-ounces, 
or one thousand times three drachms, or a like pro- 
portional quantity of blood, according to the amount 
which we assume as propelled with each stroke of the 
heart, sent from this organ into the artery; a larger 
quantity in every case than is contained in the whole 
body ! In the same way, in the sheep^ox dog, say that 
but a single scruple of blood passes with each stroke of 
the heart, in one half-hour we should havex)ne thousand 
scruples, or about three pounds and a half of blood 
injected into the aorta ; but the body of neither animal 
contains above four pounds of blood, a fact which I 
have myself ascertained in the case of the sheep. 

Upon this supposition, therefore, assumed merely as 
a ground for reasoning, we see the whole mass of blood 
passing through the heart, from the veins to the arteries, 
and in like manner through the lungs. 

But let it be said that this does not take place in half 
an hour, but in an hour, or even in a day ; any way it 

60 Motion of the 

is still manifest that more blood passes through the 
heart in consequence of its action, than can either be 
supplied by the whole of the ingesta, or than can be 
contained in the veins at the same moment. 

Nor can it be allowed that the heart in contracting 
sometimes propels and sometimes does not propel, or 
at most propels but very little, a mere nothing, or an 
imaginary something : all this, indeed, has already been 
refuted; and is, besides, contrary both to sense and 
reason. For if it be a necessary effect of the dilatation 
of the heart that its ventricles become filled with 
blood, it is equally so that, contracting, these cavities 
should expel their contents ; and this not in any trifling 
measure, seeing that neither are the conduits small, 
nor the contractions few in number, but frequent, and 
always in some certain proportion, whether it be a 
third, or a sixth, or an eighth, to the total capacity of 
the ventricles, so that a like proportion of blood must 
be expelled, and a like proportion received with each 
stroke of the heart, the capacity of the ventricle con- 
tracted always bearing a certain relation to the capacity 
of the ventricle when dilated. And since in dilating, 
the ventricles cannot be supposed to get filled with 
nothing, or with an imaginary something ; so in con- 
tracting they never expel nothing or aught imaginary, 
but always a certain something, viz. blood, in proportion 
to the amount of the contraction. Whence it is to be 
inferred, that if at one stroke the heart in man, the ox, 
or the sheep, ejects but a single drachm of blood, and 
there are one thousand strokes in half an hour, in this 
interval there will have been ten pounds five ounces 
expelled : were there with each stroke two drachms 
expelled, the quantity would of course amount to twenty 
pounds and ten ounces ; were there half an ounce, the 
quantity would come to forty-one pounds and eight 
ounces ; and were there one ounce, it would be as much 
as eighty-three pounds and four ounces ; the whole of 
which, in the course of one half-hour, would have been 

Heart and Blood 61 

transfused from the wins to the arteries. The actual 
quantity of blood expelled at each stroke of the heart, 
and the circumstances under which it is either greater 
or less than ordinary, I leave for particular determination 
afterwards, from numerous observations which I have 
mad-- on the subject. 

Meantime this much I know, and would here pro- 
claim to all, that the blood is transfused at one time 
in larger, at another in smaller quantity ; and that the 
circuit of the blood is accomplished now more rapidly, 
now more slowly, according to the temperament, a;4e, 
&c., of the individual, to external and internal circum- 
stances, to naturals and non-naturals, — sleep, rest, food, 
exercise, affections of the mind, and the like. But 
indeed, snppqsm£_py pn the smalles t qn.nntitv of blood 
to be passed through the heart and the lungs with 
eacfc pulsation, a vastly greater amount would still be 
thrown~uilja_Lb£_axteries and whole body.iEan could 
by any possibility be supplied-by- -tha food, cons umed : 
in short it could be furnished in no other way than by 
making a circuit and returning. 

This truth, indeed, presents itself obviously before 
us when we consider what happens in the dissection of 
living animals ; the great artery need not be divided, 
but a very small branch only, (as Galen even proves in 
regard to man,) to have the whole of the blood in the 
body, as well that of the veins as of the arteries, drained 
away in the course of no long time — some half-hour or 
less. Butchers are well aware of the fact and can bear 
witness to it ; for, cutting the throat of an ox and so 
dividing the vessels of the neck, in less than a quarter 
of an hour they have all the vessels bloodless — the 
whole mass of blood has escaped. The same thing 
also occasionally occurs with great rapidity in per- 
forming amputations and removing tumours in the 
human subject. 

Xor would this argument lose any of its force, did 
any one say that in killing animals in the shambles, and 

62 Motion of the 

performing amputations, the blood escaped in equal, 
if not perchance in larger quantity by the veins than by 
the arteries. The contrary of this statement, indeed, 
is certainly the truth ; the veins, in fact, collapsing, 
and being without any propelling power, and further, 
because of the impediment of the valves, as I shall 
show immediately, pour out but very little blood ; whilst 
the arteries spout it forth with force abundantly, 
impetuously, and as if it were propelled by a syringe. 
And then the experiment is easily tried of leaving the 
vein untouched, and only dividing the artery in the 
neck of a sheep or dog, when it will be seen with what 
force, in what abundance, and how quickly, the whole 
blood in the body, of the veins as well as of the 
arteries, is emptied. But the arteries receive blood 
from the veins in no other way than by transmission 
through the heart, as we have already seen ; so that if 
the aorta be tied at the base of the heart, and the 
carotid or any other artery be opened, no one will now 
be surprised to find it empty, and the veins only replete 
with blood. 

And now the cause is manifest, wherefore in our 
dissections we usually find so large a quantity of blood 
in the veins, so little in the arteries ; wherefore there is 
much in the right ventricle, little in the left ; circum- 
stances which probably led the ancients to believe 
that the arteries (as their name implies) contained 
nothing but spirits during the life of an animal. The 
true cause of the difference is this perhaps : that as 
there is no passage to the arteries, save through the 
lungs and heart, when an animal has ceased to breathe 
and the lungs to move, the blood in the pulmonary- 
artery is prevented from passing into the pulmonary 
veins, and from thence into the left ventricle of the 
heart ; just as we have already seen the same transit 
prevented in the embryo, by the want of movement in 
the lungs and the alternate opening and shutting of 
their minute orifices and invisible pores. But the 

Heart and Blood 63 

heart not ceasing to act at the same precise moment as 
the lungs, but surviving them and continuing to pulsate 
for a time, the left ventricie and arteries go on dis- 
tributing their blood to the body at large and sending 
it into the veins ; receiving none from the lungs, 
however, they are soon exhausted and left, as it were, 
empty. But even this fact confirms our views, in no 
trifling manner, seeing that it can be ascribed to no 
other than the cause we have just assumed. 

Moreover it appears from this that the more frequently 
or forcibly the arteries pulsate, the more speedily will 
the body be exhausted in an hemorrhagy. Hence, 
also, it happens, that in fainting fits and in states of 
alarm, when the heart beats more languidly and 
with less force, hemorrhages are diminished or 

Still further, it is from this that after death, when 
the heart has ceased to beat, it is impossible by dividing 
either the jugular or femoral veins and arteries, by any 
effort to force out more than one half of the whole mass 
of the blood. Neither could the butcher, did he 
I .'Ct to cut the throat of the ox which he has knocked 
on the head and stunned, until the heart had ceased 
beating, ever bleed the carcass effectually. 

Finally, we are now in a condition to suspect where- 
fore it is that no one has yet said anything to the 
purpose upon the anastomosis of the veins and arteries, 
either as to where or how it is effected, or for what 
purpose. I now enter upon the investigation of the 



So far our first position is confirmed, whether the 
thing be referred to calculation or to experiment and 
dissection, viz. that the blood is incessantly infused 
into the arteries in larger quantities than it can be 
supplied by the food ; so that the whole passing over 
in a short space of time, it is matter of necessity that 
the blood perform a circuit, that it return to whence it 
set out. 

But if any one shall here object that a large quantity 
may pass through and yet no necessity be found for a 
circulation, that all may come from the meat and drink 
consumed, and quote as an illustration the abundant 
supply of milk in the mammae — for a cow will give 
three, four, and even seven gallons and more in a day, 
and a woman two or three pints whilst nursing a child 
or twins, which must manifestly be derived from the 
food consumed ; it may be answered, that the heart by 
computation does as much and more in the course of 
an hour or two. 

And if not yet convinced, he shall still insist, that 
when an artery is divided a preternatural route is, as it 
were, opened, and that so the blood escapes in torrents, 
but that the same thing does not happen in the healthy 
and uninjured body when no outlet is made ; and that 


Motion of the Heart and Blood 65 

in arteries filled, or in their natural state, so large a 
quantity of blood cannot pass in so short a space of 
time as to make any return necessary; — to all this it 
may be answered, that from the calculation already 
made, and the reasons assigned, it appears, that by 
so much as the heart in its dilated state contains in 
addition to its contents in the state of constriction, so 
much in a general way must it emit upon each pulsa- 
tion, and in such quantity must the blood pass, the 
body being healthy and naturally constituted. 

But in serpents, and several fishes, by tying the veins 
some way below the heart, you will perceive a space 
between the ligature and the heart speedily to become 
empty ; so that, unless you would deny the evidence of 
your senses, you must needs admit the return of the 
blood to the heart. The same thing will also plainly 
appear when we come to discuss our second position. 

Let us here conclude with a single example, con- 
firming all that has been said, and from which every 
one may obtain conviction through the testimony of his 
own eyes. 

If a li ve snak e be laid open, the heart will be seen 
pulsating quietly, distinctly, for more than an hour, 
moving like a worm, contracting in its longitudinal 
dimensions, (for it is of an oblong shape,) and pro- 
pelling its contents; becoming of a paler colour in the 
systole, of a deeper tint in the diastole ; and almost all 
things else by which I have alread that the truth 

I contend for is established, only that here everyth ing 
takes jjlace more^lnwly, atMJJsjiiore distinct. This 
. point lrTparTfcular may be observed fiTOTe"~"clearly than 
the noon-day sun : the vena cava enters the heart at 
its lower part, the artery quits it at the superior part ; 
the vein being now seized either with forceps or between 
the finger and thumb, and the course of the blood for 
some space below the heart interrupted, you will preceive 
the part that intervenes between the fingers and the 
heart almost immediately to become empty, the blood 
G 262 

66 Motion of the Heart and Blood 

being exhausted by the action of the heart ; at the 
same time the heart will become of a much paler 
colour, even in. its state of dilatation, than it was before ; 
it is also smaller than at first, from wanting blood; and 
then it begins to beat more slowly, so that it seems at 
length as if it were about to die. But the impediment 
to the flow of blood being removed, instantly the colour 
and the size of the heart are restored. 

If, on the contrary, the artery instead of the vein be 
compressed or tied, you will observe the part between 
the obstacle and the heart, and the heart itself, to become 
inordinately distended, to assume a deep purple or even 
livid colour, and at length to be so much oppressed 
with blood that you will believe it about to be choked ; 
but the obstacle removed, all things immediately return 
to their pristine state — the heart to its colour, size, 
stroke, &c. 

Here then we have evidence of two kinds of death : 
extinction from deficiency, and suffocation from excess. 
Examples of both have now been set before you, and 
you have had opportunity of viewing the truth contended 
for with your own eyes in the heart. 



That this may the more clearly appear to every one, 
I have here to cite certain experiments, from which it 
seems obvious that the blood enters a limb by the 
arteries, and returns from it by the veins ; that the 
arteries are the vessels carrying the blood from 
the heart, and the veins the returning channels of 
the blood to the heart ; that in the limbs and extreme 
parts of the body the blood passes either immediately 
by anastomosis from the arteries into the veins, or 
mediately by the pores of the flesh, or in both ways, 
as has already been said in speaking of the passage of 
the blood through the lungs ; whence it appears mani- 
fest that in the circuit the blood moves from thence 
hither, and from hence thither ; from the centre to the 
extremities, to wit ; and from the extreme parts back 
again to the centre. Finally, upon grounds of calcula- 
tion, with the same elements as before, it will be 
obvious that the quantity can neither be accounted 
for by the ingesta, nor yet be held necessary to 

The same thing will also appear in regard to ligatures, 
and wherefore they are said to draw ; though this is 
neither from the heat, nor the pain, nor the vacuum 
they occasion, nor indeed from any other cause yet 
thought of; it will also explain the uses and advantages 
to be derived from ligatures in medicine, the principle 
upon which they either suppress or occasion hemor- 
rhage ; how they induce sloughing and more extensive 


68 Motion of the 

mortification in extremities ; and how they act in the 
castration of animals and the removal of warts and 
fleshy tumours. But it has come to pass, from no one 
having duly weighed and understood the causes and 
rationale of these various effects, that though almost all, 
upon the faith of the old writers, recommend ligatures in 
the treatment of disease, yet very few comprehend their 
proper employment, or derive any real assistance from 
them in effecting cures. 

Ligatures are either very tight or of middling tight- 
ness. A ligature I designate as tight or perfect when 
it is drawn so close about an extremity that no vessel 
can be felt pulsating beyond it. Such a ligature we 
use in amputations to control the flow of blood ; and 
such also are employed in the castration of animals 
and the removal of tumours. In the latter instances, 
all afflux of nutriment and heat being prevented by the 
ligature, we see the testes and large fleshy tumours 
dwindle, and die, and finally fall off. 

Ligatures of middling tightness I regard as those 
which compress a limb firmly all around, but short of 
pain, and in such a way as still suffers a certain degree 
of pulsation to be felt in the artery beyond them. Such 
a ligature is in use in blood-letting, an operation in 
which the fillet applied above the elbow is not drawn 
so tight but that the arteries at the wrist may still be felt 
beating under the finger. 

Now let any one make an experiment upon the arm 
of a man, either using such a fillet as is employed in 
blood-letting, or grasping the limb tightly with his hand, 
the best subject for it being one who is lean, and who 
has large veins, and the best time after exercise, when 
the body is warm, the pulse is full, and the blood 
carried in larger quantities to the extremities, for all 
then is more conspicuous ; under such circumstances 
let a ligature be thrown about the extremity, and drawn 
as tightly as can be borne, it will first be perceived that 
beyond the ligature, neither in the wrist, nor anywhere 

Heart and Blood 69 

else, do the arteries pulsate, at the same time that 
immediately above the ligature the artery begins to rise 
or at each diastole, to throb more violently, and to 
swell in its vicinity with a kind of tide, as if it strove to 
break through and overcome the obstacle to its current ; 
the artery, here, in short, appears as if it were preter- 
naturally full. The hand under such circumstances 
retains its natural colour and appearance ; in the course 
of time it begins to fall somewhat in temperature, in- 
deed, but nothing is drawn into it. 

After the bandage has been kept on for some short 
time in this way, let it be slackened a little, brought to 
that state or term of middling tightness which is used 
in bleeding, and it will be seen that the whole hand 
and arm will instantly become deeply suffused and 
distended, and the veins show themselves tumid and 
knotted : after ten or fifteen pulses of the artery, the 
hand will be perceived excessively distended, injected, 
gorged with blood, drawn, as it is said, by this middling 
ligature, without pain, or heat, or any horror of a 
vacuum, or any other cause yet indicated. 

If the finger be applied over the artery as it is pul- 
sating by the edge of the fillet, at the moment of 
slackening it, the blood will be felt to glide through, 
as it were, underneath the finger; and he, too, upon 
whose arm the experiment is made, when the ligature 
is slackened, is distinctly conscious of a sensation of 
warmth, and of something, viz. a stream of blood, 
suddenly making its way along the course of the 
vessels' and diffusing itself through the hand, which 
at the same time begins to feel hot, and becomes 

As we had noted, in connexion with the tight ligature, 
that the artery above the bandage was distended and 
pulsated, not below it, so, in the case of the moderately 
tight bandage, on the contrary, do we find that the veins 
below, never above, the fillet, swell, and become dilated, 
whilst the arteries shrink ; and such is the degree of 

70 Motion of the 

distension of the veins here, that it is only very strong 
pressure that will force the blood beyond the fillet, and 
cause any of the veins in the upper part of the arm 
to rise. 

From these facts it is easy for every careful observer 
to learn that the blood enters an extremity by the 
arteries ; for when they are effectually compressed 
nothing is drawn to the member ; the hand preserves 
its colour ; nothing flows into it, neither is it distended ; 
but when the pressure is diminished, as it is with the 
bleeding fillet, it is manifest that the blood is instantly 
thrown in with force, for then the hand begins to swell ; 
which is as much as to say, that when the arteries 
pulsate the blood is flowing through them, as it is when 
the moderately tight ligature is applied ; but where they 
do not pulsate, as when a tight ligature is used, they 
cease from transmitting anything ; they are only dis- 
tended above the part where the ligature is applied. 
The veins again being compressed, nothing can flow 
through them ; the certain indication of which is, that 
below the ligature they are much more tumid than 
above it, and than they usually appear when there is no 
bandage upon the arm. 

It therefore plainly appears that the ligature prevents 
the return., of the blood through the veins to the parts 
above it, and maintains those beneath it rrra~5Tafe~~of 
permanent distension. But the arteries, in spite of its 
pressure, and under the force and impulse of the heart, 
send on the blood from the internal parts of the body 
to the parts beyond the bandage. And herein consists 
the difference between the tight and the medium 
bandage, that the former not only prevents the passage 
of the blood in the veins, but in the arteries also ; the 
latter, however, whilst it does not prevent the pulsific 
force from extending beyond it, and so propelling the 
blood to the extremities of the body, compresses the 
veins, and greatly or altogether impedes the return of 
the blood through them. 

Heart and Blood 71 

Seeing, therefore, that the moderately tight ligature 

renders the veins turgid, and the whole hand full of 
blood, I ask, whence is this? Does the blood accu- 
mulate below the ligature coming through the veins, or 
through the arteries, or passing by certain secret pores? 
Through the veins it cannot come ; still less can it 
come by any system of invisible pores; it must needs 
arrive by the arteries, then, in conformity with all that 
has been already said. That it cannot flow in by the 
veins appears plainly enough from the fact that the 
blood cannot be forced towards the heart unless 
the ligature be removed ; when on a sudden all the 
veins collapse, and disgorge themselves of their contents 
into the superior parts, the hand at the same time 
r< suming its natural pale colour — the tumefaction and 
the stagnating blood have disappeared. 

Moreover, he whose arm or wrist has thus been 
bound for some littlejime with the medium bandage, 
so tfTaTlt has not only got swollen and livid but cold, 
when the fillet is undone is aware of something cold 
making its way upwards along with the returning blood, 
and reaching the elbow or the axilla. And I have 
myself been inclined to think that this cold blood 
rising upward to the heart was the cause of the fainting 
that often occurs after blood-letting : fainting frequently 
supervenes even in robust subjects, and mostly at the 
moment of undoing the fillet, as the vulgar say, from 
the turning of the blood. 

Farther, when we see the veins below the ligature 
instantly swell up and become gqrged7~when from 
extreme tightness it is somewhat relaxed, the arteries 
meantime continuing unaffected, this is an obvious 
indication that the blood passes from the arteries into 
the_y_eins, and not from the veins intojt he arteries , and 
that there is either an anastomosis of the two orders of 
vessels, or pores in the flesh and solid parts generally 
that are permeable to the blood. It is farther an 
indication that the veins have frequent communications 

72 Motion of the 

with one another, because they all become turgid 
together, whilst under the medium ligature applied 
above the elbow ; and if any single small vein be 
pricked with a lancet, they all speedily shrink, and 
disburdening themselves into this they subside almost 

These considerations will enable any one to under- 
stand the nature of the attraction that is exerted by 
ligatures, and perchance of fluxes generally ; how, for 
example, the veins when compressed by a bandage of 
medium tightness applied above the elbow, the blood 
cannot escape, whilst it still continues to be driven in, 
to wit, by the forcing power of the heart, by which the 
parts are of necessity filled, gorged with blood. And 
how should it be otherwise ? Heat and pain and the 
vis vacui draw, indeed ; but in such wise only that parts 
are filled, not preternaturally distended or gorged, not 
so suddenly and violently overwhelmed with the charge 
of blood forced in upon them, that the flesh is lacerated 
and the vessels ruptured. Nothing of the kind as an 
effect of heat, or pain, or the vacuum force, is either 
credible or demonstrable. 

Besides, the ligature is competent to occasion the 
afflux in question without either pain, or heat, or vis 
vacui. Were pain in any way the cause, how should 
it happen that, with the arm bound above the elbow, 
the hand and fingers should swell below the bandage, 
and their veins become distended? The pressure of 
the bandage certainly prevents the blood from getting 
there by the veins. And then, wherefore is there 
neither swelling nor repletion of the veins, nor any 
sign or symptom of attraction or afflux, above the 
ligature ? But this is the obvious cause of the preter- 
natural attraction and swelling below the bandage, and 
in the hand and fingers, that the blood is entering 
abundantly, and with force, but cannot pass out 

Now, is not this the cause of all tumefaction, as 

Heart and Blood 73 

indeed Avicenna has it, and of all oppressive redun- 
dancy in parts, that the access to them is open, but 
the egress from them is closed ? Whence it comes 
that they are gorged and tumefied. And may not the 
same thing happen in local inflammations, where, so 
long as the swelling is on the increase, and has not 
reached its extreme term, a full pulse is felt in the 
part, especially svhen the disease is of the more acute 
kind, and the swelling usually takes place most rapidly. 
But these are matters for after discussion. Or does 
this, which occurred in my own case, happen from 
the same cause ? Thrown from a carriage upon one 
occasion, I struck my forehead a blow upon the place 
where a twig of the artery advances from the temple, 
and immediately, within the time in which twenty beats 
could have been made, I felt a tumour the size of an 
egg developed, without either heat or any great pain : 
the near vicinity of the artery had caused the blood 
to be effused into the bruised part with unusual force 
and quickness. 

And now, too, we understand wherefore in phlebo- 
tomy we apply our fillet above the part that is punctured, 
not below it ; did the flow come from above, not from 
below, the bandage in this case would not only be 
of no service, but would prove a positive hinderance ; 
it would have to be applied below the orifice, in order 
to have the flow more free, did the blood descend by 
the veins from superior to inferior parts ; but as it is 
elsewhere forced through the extreme arteries into the 
extreme veins, and the return in these last is opposed 
by the ligature, so do they fill and swell, and being 
thus filled and distended, they are made capable of 
projecting their charge with force, and to a distance, 
when any one of them is suddenly punctured ; but 
the fillet being slackened, and the returning channels 
thus left open, the blood forthwith no longer escapes, 
save by drops ; and, as all the world knows, if in per- 
forming phlebotomy the bandage be either slackened 

74 Motion of the Heart and Blood 

too much or the limb be bound too tightly, the blood 
escapes without force, because in the one case the 
returning channels are not adequately obstructed; in 
the other the channels of influx, the arteries, are 



If these things be so, another point which I have 
already referred to, viz. the continual passage of the 
blood through the heart, will also be confirmed. We 
have seen, that the blood passes from the arteries into 
the veins, not from the veins into the arteries ; we 
have seen, farther, that almost the whole of the blood 
may be withdrawn from a puncture made in one of 
the cutaneous veins of the arm if a bandage properly 
applied be used; we have seen, still farther, that the 
blood flows so freely and rapidly that not only is the 
whole quantity which was contained in the arm beyond 
the ligature, and before the puncture was made, dis- 
charged, but the whole which is contained in the body, 
both that of the arteries and that of the veins. 

Whence we must admit, first, that the blood is sent 
along with an impulse, and that it is urged with force 
below the fillet ; for it escapes with force, which force 
it receives from the pulse and power of the heart ; 
for the force and motion of the blood are derived from 
the heart alone. Second, that the afflux proceeds from 
the heart, and through the heart by a course from the 
great veins [into the aorta] ; for it gets into the parts 
below the ligature through the arteries, not through 
the veins ; and the arteries nowhere receive blood 
from the veins, nowhere receive blood save and except 
from the left ventricle of the heart. Nor could so 
large a quantity of blood be drawn from one vein 


7 6 

Motion of the 

(a ligature having been duly applied), nor with such 
impetuosity, such readiness, such celerity, unless 
through the medium of the impelling power of the 

But if all things be as they are now represented, 
we shall feel ourselves at liberty to calculate the 
quantity of the blood, and to reason on its circular 
motion. Should any one, for instance, in performing 
phlebotomy, suffer the blood to flow in the manner it 
usually does, with force and freely, for some half-hour 
or so, no question but that the greatest part of the 
blood being abstracted, faintings and syncopes would 
ensue, and that not only would the arteries but the 
great veins also be nearly emptied of their contents. It 
is only consonant with reason to conclude that in the 
course of the half-hour hinted at, so much as has 
escaped has also passed from the great veins through 
the heart into the aorta. And further, if we calculate 
how many ounces flow through one arm, or how many 
pass in twenty or thirty pulsations under the medium 
ligature, we shall have some grounds for estimating 
how much passes through the other arm in the same 
space of time ; how much through both lower ex- 
tremities, how much through the neck on either side, 
and through all the other arteries and veins of the 
body, all of which have been supplied with fresh blood, 
and as this blood must have passed through the lungs 
and ventricles of the heart, and must have come from 
the great veins, — we shall perceive that a circulation 
is absolutely necessary, seeing that the quantities-hinted 
at cannot be supplied immediately from i.he ingesta, 
and are vastly more than can be requisite for the mere 
nutrition of the parts. 

It is still further to be observed, that the truths 
contended for are sometimes confirmed in another 
way ; for having tied up the arm properly, and made 
the puncture duly, still, if from alarm or any other 
causes, a state of faintness supervenes, in which the 

Heart and Blood 77 

heart always pulsates more languidly, the blood does 
not flow freely, hut distils hydrops only. The reason 
is, that with the somewhat greater than usual resistance 
offered to the transit of the blood by the bandage, 
coupled with the weaker action of the heart, and its 
diminished impelling power, the stream cannot make 
its way under the fillet ; and farther, owing to the weak 
and languishing state of the heart, the blood is not 
transferred in such quantity as wont from the veins 
to the arteries through the sinuses of that organ. So 
also, and for the same reasons, are the menstrual fluxes 
of women, and indeed hemorrhagies of every kind, 
controlled. And now, a contrary state of things occur- 
ring, the patient getting rid of his fear and recovering 
his courage, the pulsific power is increased, the arteries 
begin again to beat with greater force, and to drive 
the blood even into the part that is bound ; so that 
the blood now springs from the puncture in the vein, 
and flows in a continuous stream. 



Thus far have we spoken of the quantity of blood 
passing through the heart and the lungs in the centre 
of the body, and in like manner from the arteries into 
the veins in the peripheral parts and the body at large. 
We have yet to explain, however, in what manner the 
blood finds its way back to the heart from the ex- 
tremities by the veins, and how and in what way these 
are the only vessels that convey the blood from the 
external to the central parts ; which done, I conceive 
that the three fundamental propositions laid down for 
the circulation of the blood will be so plain, so well 
established, so obviously true, that they may claim 
general credence. Now the remaining position will be 
made sufficiently clear from the valves which are 
found in the cavities of the veins themselves, from the 
uses of these, and from experiments cognizable by the 

The celebrated Hieronymus Fabricius of Aquapen- 
dente, a most skilful anatomist, and venerable old man, 
or, as the learned Riolan will have it, Jacobus Silvius, 
first gave representations of the valves in the veins, 
which consist of raised or loose portions of the inner 
membranes of these vessels, of extreme delicacy, and 
a sigmoid or semilunar shape. They are situated at 
different distances from one another, and diversely in 
different individuals ; they are connate at the sides of 
the veins ; they are directed upwards or towards the 


Motion of the Heart and Blood 79 

trunks of the veins ; the two — for there are for the 
most part two together — regard each other, mutually 
touch, and are so ready to come into contact by their 
edges, that if anything attempt to pass from the trunks 
into the branches of the veins, or from the greater 
I Is into the less, they completely prevent it ; they 
are farther so arranged, that the horns of those that 
succeed are opposite the middle of the convexity of 
those that precede, and so on alternately. 

The discoverer of these valves did not rightly under- 
their use, nor have succeeding anatomists added any- 
thing to our knowledge : for their office is by no means 
explained when we are told that it is to hinder the 
blood, by its weight, from all flowing into inferior 
parts ; for the edges of the valves in the jugular veins 
hang downwards, and are so contrived that they 
prevent the blood from rising upwards ; the valves, 
in a word, do not invariably look upwards, but always 
towards the trunks of the veins, invariably towards the 
seat of the heart. I, and indeed others, have some- 
times found valves in the emulgent veins, and in those 
of the mesentery, the edges of which were directed 
towards the vena cava and vena portae. Let it be 
added that there are no valves in the arteries [save at 
their roots], and that dogs, oxen, &c, have invariably 
valves at the divisions of their crural veins, in the veins 
that meet towards the top of the os sacrum, and in 
those branches which come from the haunches, in 
which no such effect of gravity from the erect position 
was to be apprehended. Neither are there valves in 
the jugular veins for the purpose of guarding against 
apoplexy, as some have said ; because in sleep the 
head is more apt to be influenced by the contents of 
the carotid arteries. Neither are the valves present, in 
order that the blood may be retained in the divarica- 
tions or smaller trunks and minuter branches, and not 
be suffered to flow entirely into the more open and 
capacious channels ; for they occur where there are no 


Motion of the 

irications; although it must be owned that they 
"are most frequent at the points where branches join. 
Neither do they exist for the purpose of rendering 
the current of blood more slow from the centre of the 
body ; for it seems likely that the blood would be dis- 
posed to flow with sufficient slowness of its own accord, 
as it would have to pass from larger into continually 
smaller vessels, being separated from the mass and 
fountain head, and attaining from warmer into colder 

But the valves are solely made and instituted lest the 
blood should pass from the greater into the lesser veins, 
and either rupture them or cause them to become 
varicose ; lest, instead of advancing from the extreme 
to the central parts of the body, the blood should 
rather proceed along the veins from the centre to the 
extremities ; but the delicate valves, while they readily 
open in the right direction, entirely prevent all such 
contrary motion, being so situated and arranged, that 
if anything escapes, or is less perfectly obstructed by 
the cornua of the one above, the fluid passing, as it 
were, by the chinks between the cornua, it is imme- 
diately received on the convexity of the one beneath, 
which is placed transversely with reference to the 
former, and so is effectually hindered from getting any 

And this I have frequently experienced in my dis- 
sections of the veins : if I attempted to pass a probe 
from the trunk of the veins into one of the smaller 
branches, whatever care I took I found it impossible 
to introduce it far any way, by reason of the valves ; 
whilst, on the contrary, it was most easy to push it 
along in the opposite direction, from without inwards, 
or from the branches towards the trunks and roots. 
In many places two valves are so placed and fitted, 
that when raised they come exactly together in the 
middle of the vein, and are there united by the contact 
of their margins; and so accurate is the adaptation, 

Heart and Blood 81 

that neither by the eye nor by any other means of 
examination can the slightest chink along the line 
of contact be perceived. But if the probe be now 
introduced from the extreme towards the more central 
parts, the valves, like the floodgates of a river, give 
way, and are most readily pushed aside. The effect 
of this arrangement plainly is to prevent all motion of 
the blood from the heart and vena cava, whether it be 
upwards towards the head, or downwards towards the 
feet, or to either side towards the arms, not a drop can 
pass ; all motion of the blood, beginning in the larger 
and tending towards the smaller veins, is opposed and 
resisted by them ; whilst the motion that proceeds from 
the lesser to end in the larger branches is favoured, or, 
at all events, a free and open passage is left for it. 

But that this truth may be made the more apparent, 
let an arm be tied up above the elbow as if for 
phlebotomy (a, a, fig. i). At intervals in the course 
of the veins, especially in labouring people and those 
whose veins are large, certain knots or elevations (b, c, 
d, e, f) will be perceived, and this not only at the 
places where a branch is received (e, f), but also where 
none enters (c, d) : these knots or risings are all formed 
by valves, which thus show themselves externally. And 
now if you press the blood from the space above one of 
the valves, from H to o, (fig. 2,) and keep the point of 
a finger upon the vein inferiorly, you will see no influx 
of blood from above ; the portion of the vein between the 
point of the finger and the valve o will be obliterated ; 
yet will the vessel continue sufficiently distended above 
that valve (o, g). The blood being thus pressed out, 
and the vein emptied, if you now apply a finger of the 
other hand upon the distended part of the vein above 
the valve o, (fig. 3,) and press downwards, you will find 
that you cannot force the blood through or beyond the 
valve; but the greater effort you use, you will only see 
the portion of vein that is between the finger and the 
valve become more distended, that portion of the vein 
H 262 

82 Motion of the Heart and Blood 

which is below the valve remaining all the while empty 
(h, o, fig. 3). 

It would therefore appear that the function of the 
valves in the veins is the same as that of the three 
sigmoid valves which we find at the commencement of 
the aorta and pulmonary artery, viz., to prevent all 
reflux of the blood that is passing over them. 

Farther, the arm being bound as before, and the 
veins looking full and distended, if you press at one 
part in the course of a vein with the point of a finger 
(l, fig. 4), and then with another finger streak the blood 
upwards beyond the next valve (n), you will perceive 
that this portion of the vein continues empty (l n), 
and that the blood cannot retrogade, precisely as we 
have already seen the case to be in fig. 2 ; but the 
finger first applied (h, fig. 2, l, fig. 4), being removed, 
immediately the vein is filled from below, and the arm 
becomes as it appears at d c, fig. 1. That the blood 
in the veins therefore proceeds from inferior or more 
remote to superior parts, and towards the heart, moving 
in these vessels in this and not in the contrary direc- 
tion, appears most obviously. And although in some 
places the valves, by not acting with such perfect 
accuracy, or where there is but a single valve, do not 
seem totally to prevent the passage of the blood from 
the centre, still the greater number of them plainly do 
so ; and then, where things appear contrived more 
negligently, this is compensated either by the more 
frequent occurrence or more perfect action of the suc- 
ceeding valves or in some other way : the veins, in 
short, as they are the free and open conduits of the 
blood returning to the heart, so are they effectually 
prevented from serving as its channels of distribution 
from the heart. 

But this other circumstance has to be noted : The 
arm being bound, and the veins made turgid, and the 
valves prominent, as before apply the thumb or finger 
over a vein in the situation of one of the valves in such 


84 Motion of the Heart and Blood 

a way as to compress it, and prevent any blood from 
passing upwards from the hand ; then, with a finger of 
the other hand, streak the blood in the vein upwards 
till it has passed the next valve above, (n, fig. 4,) the 
vessel now remains empty ; but the finger at l being 
removed for an instant, the vein is immediately filled 
from below ; apply the finger again, and having in the 
same manner streaked the blood upwards, again remove 
the finger below, and again the vessel becomes dis- 
tended as before ; and this repeat, say a thousand times, 
in a short space of time. And now compute the quantity 
of blood which you have thus pressed up beyond the 
valve, and then multiplying the assumed quantity by 
one thousand, you will find that so much blood has 
passed through a certain portion of the vessel ; and 
I do now believe that you will find yourself convinced 
of the circulation of the blood, and of its rapid motion. 
But if in this experiment you say that a violence is done 
to nature, I do not doubt but that, if you proceed in 
the same way, only taking as great a length of vein as 
possible, and merely remark with what rapidity the 
blood flows upwards, and fills the vessel from below, 
you will come to the same conclusion. 



And now I may be allowed to give in brief my view 
of the circulation of the blood, and to propose it for 
general adoption. 

Since all things, both argument and ocular demon- 
stration, show that the blood passes through the lungs 
and heart by the action of the [auricles and] ventricles, 
and is sent for distribution to all parts of the body, 
where it makes its way into the veins and pores of the 
flesh, and th en flows by the veins from the circum- 
ference on every side to the centre, from the lesser to 
the greater veins, and is by them finally discharged into 
the vena cava and right auricle of the heart, and this in 
such a quantity or in such a flux and reflux thither by the 
arteries, hither by the veins, as cannot possibly be sup- 
plied by the ingesta, and is much greater than can be 
required for mere purposes of nutrition ; it is absolutely 
necessary to conclude that the blood in the animal body 
is impelled in a circle, and is in a state of ceaseless 
motion ; that this is the act or function which the heart 
performs by means of its pulse ; and that it is the 
sole and only end of the motion and contraction of the 




It will not be foreign to the subject if I here show 
further, from certain familiar reasonings, that the circu- 
lation is matter both of convenience and necessity. 
In the first place, since death is a corruption which 
takes place through deficiency of heat, 1 and since all 
living things are warm, all dying things cold, there must 
be a particular seat and fountain, a kind of home and 
hearth, where the cherisher of nature, the original of 
the native fire, is stored and preserved ; whence h,S3t 
and life are dispensed to all parts as from a fountain 
head ; whence sustenance may be derived ; and upon 
which concoction and nutrition, and all vegetative energy 
may depend. Now, that the heart is this place, that the 
heart is the principle of life, and that all passes in the 
manner just mentioned, I trust no one will deny. 

The blood, therefore, required to have-motion, and 
indeed such a motion that it should return again to the 
heart; for sent to the external parts of the body far from 
'its fountain, as Aristotle says, and without motion, it 
would become congealed. For we see motion generating 
and keeping up heat and spirits under all circumstances, 
and rest allowing them to escape and be dissipated. 
The blood, therefore, become thick or congealed by the 
cold of the extreme and outward parts, and robbed of 
its spirits, just as it is in the dead, it was imperative 
that from its fount and origin, it should again receive 

' Aristoteles De Respiratione, lib. ii et iii : De Part. Animal, et alibi. 


Motion of the Heart and Blood 87 

heat and spirits, and all vise requisite to its preservation — 
that, by returning, it should be renovated and restored. 

We frequently see how the extremities are chilled by 
the external cold, how the nose and cheeks and hands 
look blue, and how the blood, stagnating in them as in 
the pendent or lower parts of a corpse, becomes of a 
dusky hue ; the limbs at the same time getting torpid, 
so that they can scarcely be moved, and seem almost 
to have lost their vitality. Now they can by no means 
be so effectually, and especially so speedily restored 
to heat and colour and life, as by a new afflux and 
appulsion of heat from its source. But how can parts 
attract in which the heat and life are almost extinct ? 
Or how should thev whose passages are filled with 
conden.^d and frigid blond, admit fresh aliment — 
ren6v ated blo od — unl ess thev had fi rst got rid of their 
old co nt ents t Unless the heart were truly that fou ntain 
where life and heat are restored to the refrigerated fluid, 
and whence n ew bl ood, warm, imbued with spirits, 
being sent out b v the art eries, that which has become 
cooled anoT' gjTeTe^i s forced on, and all the particles 
recov er their^he at~which was failing, and their vital 
stimulus well-nigh exhausted. 

Hence it is that if the heart be unaffected, life and 
health may be restored to almost all the other parts 
of the body ; but the heart being chilled, or smitten 
with any serious disease, it seems matter of necessity 
that the whole animal fabric should suffer and fall into 
decay. When the *<"".-* ; s rorniptf^, * h f;rf is nothing, 
as Aristotle says, 1 which can b e of servi ce eit her _t o it or 
aught that d*4itmds_on it. "And hence", by the way, it 
may perchance be wherefore grief, and love, and envy, 
and anxiety, and all affections of the mind of a similar 
kind are accompanied with emaciation and decay, or 
with cacochemy and crudity, which engender all manner 
of diseases and consume the body of man. For every 
affection of the mind that is attended with either pain 

1 De Part. Animal, iii. 

83 Motion of the 

or pleasure, hope or fear, is the cause of an agitation 
whose influence extends to the heart, and there induces 
change from the natural constitution, in the temperature, 
the pulse and the rest, which impairing all nutrition in 
its source and abating the powers at large, it is no 
wonder that various forms of incurable disease in the 
extremities and in the trunk are the consequence, 
inasmuch as in such circumstances the whole body 
labours under the effects of vitiated nutrition and 
a want of native heat. 

Moreover, when we see that all animals live through 
food concocted in their interior, it is imperative that 
the digestion and distribution be perfect ; and, as a 
consequence, that there be a place and receptacle where 
the aliment is perfected and whence it is distributed to 
the several members. Now this place is the heart, for 
it is the only organ in the body which contains blood 
for the general use ; all the others receive it merely for 
their peculiar or private advantage, just as the heart also 
has a supply for its own especial behoof in its coronary 
veins and arteries ; but it is of the store which the heart 
contains in its auricles and ventricles that I here speak; 
and then the heart is the only organ which is so 
situated and constituted that it can distribute the blood 
in due proportion to the several parts of the body, the 
quantity sent to each being according to the dimensions 
of the artery which supplies it, the heart serving as 
a magazine or fountain ready to meet its demands. 

Further, a certain impulse or force, as well as an 
impeller or forcer, such as the heart, was required to 
effect this distribution and motion of the blood ; both 
because the blood is disposed from slight causes, such 
as cold, alarm, horror, and the like, to collect in its 
source, to concentrate like parts to a whole, or the 
drops of water spilt upon a table to the mass of liquid ; 
and then because it is forced from the capillary veins 
into the smaller ramifications, and from these into the 
larger trunks by the motion of the extremities and the 

Heart and Bloo 1 89 

compression of the muscle-, generally. The blood is 
thus more disposed to move from the circumference to 
the centre than in the opposite direction, were there 
even no valves to oppose its motion ; whence that it may 
leave its source and enter more confined and colder 
channels, and flow against the direction to which it 
spontaneously inclines, the blood requires hoth force 
and an impelling power. Now such is the heart and 
the heart alone, and that in the way and manner 
already explained. 



There are still certain phenomena, which, taken as 
consequences of this truth assumed as proven, are not 
without their use in exciting belief, as it were, a 
posteriore ; and which, although they may seem to be 
involved in much doubt and obscurity, nevertheless 
readily admit of having reasons and causes assigned 
for them. The phenomena alluded to are those that 
present themselves in connexion with contagions, 
poisoned wounds, the bites of serpents and rabid 
animals, lues venerea and the like. We sometimes 
see the whole system contaminated, though the part 
first infected remains sound ; the lues venerea has 
occasionally made its attack with pains in the shoulders 
and head, and other symptoms, the genital organs being 
all the while unaffected ; and then we know that the 
wound made by a rabid dog having healed, fever and 
a train of disastrous symptoms nevertheless supervene. 
Whence it appears that the contagion impressed upon 
or deposited in a particular part, is by and by carried 
by the returning current of blood to the heart, and by 
that organ is sent to contaminate the whole body. 

In tertian fever, the morbific cause seeking the heart 
in the first instance, and hanging about the heart and 
lungs, renders the patient short-winded, disposed to 
sighing, indisposed to exertion ; because the vital 
principle is oppressed and the blood forced into the 
lungs and rendered thick, does not pass through their 


Motion of the Heart and Blood 91 

substance, (as I have myself seen in opening the bodies 
of those who had died in the beginning of the attack,) 
when the pulse is always frequent, small, and occasionally 
irregular ; but the heat increasing, the matter becoming 
attenuated, the passages forced, and the transit made, 
the whole body begins to rise in temperature, and the 
pulse becomes fuller, stronger — the febrile paroxysm is 
fully formed, whilst the preternatural heat kindled in 
the heart, is thence diffused by the arteries through the 
whole body along with the morbific matter, which is in 
this way overcome and dissolved by nature. 

When we perceive, further, that medicines applied 
externally exert their influence on the body just as 
if they had been taken internally, the truth we are con- 
tending for is confirmed. Colocynth and aloes [applied 
externally] move the belly, cantharides excites the urine, 
garlic applied to the soles of the feet assists expectora- 
tion, cordials strengthen, and an infinite number of 
examples of the same kind might be cited. It will 
not, therefore, be found unreasonable perchance, if we 
say that the veins, by means of their orifices, absorb 
some of the things that are applied externally and 
carry this inwards with the blood, not otherwise, it 
may be, than those of the mesentery imbibe the chyle 
from the intestines and carry it mixed with the blood 
to the liver. For the blood entering the mesentery 
by the cceliac artery, and the superior and inferior 
mesenteries, proceeds to the intestines, from which, 
along with the chyle that has been attracted into the 
veins, it returns by their numerous ramifications into 
the vena portae of the liver, and from this into the 
vena cava, and this in such wise that the blood in these 
veins has the same colour and consistency as in other 
veins, in opposition to what many believe to be the 
fact. Nor indeed can we imagine two contrary motions 
in any capillary system — the chyle upwards, the blood 
downwards. This could scarcely take place, and must 
be held as altogether improbable. But is not the thing 

92 Motion of the 

rather arranged as it is by the consummate providence 
of nature? For were the chyle mingled with the blood, 
the crude with the concocted, in equal proportions, the 
result would not be concoction, transmutation, and 
sanguification, but rather, and because they are 
severally active and passive, a mixture or combina- 
tion, or medium compound of the two, precisely as 
happens when wine is mixed with water and syrup. 
But when a very minute quantity of chyle is mingled 
with a very large quantity of circulating blood, a 
quantity of chyle that bears no kind of proportion to 
the mass of blood, the effect is the same, as Aristotle 
says, as when a drop of water is added to a cask of 
wine, or the contrary ; the mass does not then present 
itself as a mixture, but is still sensibly either wine or 
water. So in the mesenteric veins of an animal we do 
not find either chyme or chyle and blood, blended 
together or distinct, but only blood, the same in colour, 
consistency, and other sensible properties, as it appears 
in the veins generally. Still as there is a certain though 
small and inappreciable proportion of chyle or uncon- 
cocted matter mingled with this blood, nature has inter- 
posed the liver, in whose meandering channels it suffers 
delay and undergoes additional change, lest arriving 
prematurely and crude at the heart, it should oppress 
the vital principle. Hence in the embryo, there is 
almost no use for the liver, but the umbilical vein 
passes directly through, a foramen or anastomosis 
existing from the vena portas, so that the blood 
returns from the intestines of the foetus, not through 
the liver, but into the umbilical vein mentioned, and 
flows at once into the heart, mingled with the natural 
blood which is returning from the placenta : whence 
also it is that in the development of the foetus the liver 
is one of the organs that is last formed; I have observed 
all the members perfectly marked out in the human 
foetus, even the genital organs, whilst there was yet 
scarcely any trace of the liver. And indeed at the 

Heart and Blood 93 

period when all the parts, like the heart itself in the 
beginning, are still white, and save in the veins there 
is no appearance of redness, you shall see nothing in 
the seat of the liver but a shapeless collection, as it 
were, of extravasated blood, which you might take for 
the effects of a contusion or ruptured vein. 

But in the incubated egg there are, as it were, two 
umbilical vessels, one from the albumen passing entire 
through the liver, and going straight to the heart ; 
another from the yelk, ending in the vena portre ; for 
it appears that the chick, in the first instance, is entirely 
formed and nourished by the white ; but by the yelk 
after it has come to perfection and is excluded from 
the shell ; for this part may still be found in the 
abdomen of the chick many days after its exclusion, 
and is a substitute for the milk to other animals. 

But these matters will be better spoken of in my 
observations on the formation of the foetus, where 
many propositions, the following among the number, 
will be discussed : Wherefore is this part formed or 
perfected first, that last ? — and of the several members : 
what part is the cause of another ? And many points 
having special reference to the heart, such as : Where- 
fore does it first acquire consistency, and appear to 
possess life, motion, sense, before any other part of the 
body is perfected, as Aristotle says in his third book, 
De partibus Animalium ? And so also of the blood : 
Wherefore does it precede all the rest? And in what 
way does it possess the vital and animal principle ? 
And show a tendency to motion, and to be impelled 
hither and thither, the end for which the heart appears 
to be made ? In the same way, in considering the 
pulse : Wherefore one kind of pulse should indicate 
death, another recovery ? And so of all the other 
kinds of pulse, what may be the cause and indication 
of each. So also in the consideration of crises and 
natural critical discharges ; of nutrition, and especially 
the distribution of the nutriment ; and of defiuxions of 

94 Motion of the 

every description. Finally, reflecting on every part of 
medicine, physiology, pathology, semeiotics, therapeutics, 
when I see how many questions can be answered, how 
many doubts resolved, how much obscurity illustrated, 
by the truth we have declared, the light we have made 
to shine, I see a field of such vast extent in which I 
might proceed so far, and expatiate so widely, that this 
my tractate would not only swell out into a volume, 
which was beyond my purpose, but my whole life, 
perchance, would not suffice for its completion. 

In this place, therefore, and that indeed in a single 
chapter, I shall only endeavour to refer the various 
particulars that present themselves in the dissection 
of the heart and arteries to their several uses and 
causes ; for so I shall meet with many things which 
receive light from the truth I have been contending 
for, and which, in their turn, render it more obvious. 
And indeed I would have it confirmed and illustrated 
by anatomical arguments above all others. 

There is but a single point which indeed would be 
more correctly placed among our observations on the 
use of the spleen, but which it will not be altogether 
impertinent to notice in this place incidentally. From 
the splenic branch which passes into the pancreas, and 
from the upper part, arise the posterior coronary, gastric, 
and gastroepiploic veins, all of which are distributed 
upon the stomach in numerous branches and twigs, 
just as the mesenteric vessels are upon the intestines ; 
in like manner, from the inferior part of the same 
splenic branch, and along the back of the colon and 
rectum proceed the hemorrhoidal veins. The blood 
returning by these veins, and bringing the cruder juices 
along with it, on the one hand from the stomach, where 
they are thin, watery, and not yet perfectly chylified ; 
on the other thick and more earthy, as derived from 
the fasces, but all poured into this splenic branch, are 
duly tempered by the admixture of contraries ; and 
nature mingling together these two kinds of juices, 

1 1 cart and Blood 95 

difficult of coction by reason of most opposite defects, 
and then diluting them with a large quantity of warm 
blood, (for we see that the quantity returned from tin- 
spleen must be very large when we contemplate the size 
of its arteries,) they are brought to tin porta of the liver 
in a state of higher preparation ; the defects of either ex- 
treme are supplied and compensated by this arrangement 
of the veins. 



I DO not find the heart as a distinct and separate part 
in all animals ; some, indeed, such as the zoophytes, 
have no heart ; this is because these animals are coldest, 
of no great bulk, of soft texture or of a certain uniform 
sameness or simplicity of structure ; among the number 
I may instance grubs and earth-worms, and those that 
are engendered of putrefaction and do not preserve 
their species. These have no heart, as not requiring 
any impeller of nourishment into the extreme parts ; 
for they have bodies which are connate and homo- 
geneous, and without limbs; so that by the contraction 
and relaxation of the whole body they assume and 
expel, move and remove the aliment. Oysters, mussels, 
sponges, and the whole genus of zoophytes or plant- 
animals have no heart ; for the whole body is used as a 
heart, or the whole animal is a heart. In a great number 
of animals, almost the whole tribe of insects, we cannot 
see distinctly by reason of the smallness of the body ; 
still in bees, flies, hornets, and the like, we can perceive 
something pulsating with the help of a magnifying glass ; 
in pediculi, also, the same thing may be seen, and as 
the body is transparent, the passage of the food through 
the intestines, like a black spot or stain, may be 
perceived by the aid of the same magnifying glass. 

In some of the bloodless i and colder animals, 

' [i.e. Not having red blood.] 


Motion of the Heart and Blood 97 

further, as in snails, whelks, shrimps, and shell-fish, 
there is a part which pulsates — a kind of vesicle or 
auricle with tut a heart — slowly indeed, and not to be 
perceived save in the warmer season of the year. In 
these creatures this part is so contrived that it shall 
pulsate, as there is here a necessity for some impulse to 
distribute the nutritive fluid, by reason of the variety of 
organic parts, or of the density of the substance ; hut 
the puls.ui' us occur unfrequently, and sometimes in 
consequence of the cold not at all, an arrangement the 
best adapted to them as being of a doubtful nature, 
so that sometimes they appear to live, sometimes to 
die ; sometimes they show the vitality of an animal, 
sometimes of a vegetable. This seems also to be the 
case with the insects which conceal themselves in 
winter, and lie, as it were, defunct, or merely manifest- 
ing a kind of vegetative existence. But whether the 
same thing happens in the case of certain animals 
that have red blood, such as frogs, tortoises, serpents, 
swallows, may be made a question without any kind of 

In all the larger and warmer, because [red-] blooded 
animals, there was need of an impeller of the nutritive 
fluid, and that perchance possessing a considerable 
amount of power. In fishes, serpents, lizards, tortoises, 
frogs, and others of the same kind there is a heart 
present, furnished with both an auricle and a ventricle, 
whence it is perfectly true, as Aristotle has observed, 1 
that no [red] blooded animal is without a heart, by the 
impelling power of which the nutritive fluid is forced, 
both with greater vigour and rapidity to a greater 
distance ; it is not merely agitated by an auricle as it is 
in lower forms. And then in regajd_tp animals that 
are yet larger, warmer, and mofe perfect, as they 
abound in blood, which is ever .h otter and more 
spirituous, and possess bodies of greater size and con- 
sistency, they require a larger, stronger, and more 

* De Part. Animal, lib. iii. 
I .162 


Motion of the 

fleshy heart, in order that the nutritive fluid may be 
propelled with yet greater force and celerity. And 
further, inasmuch as the more perfect animals require a 
still more perfect nutrition, and a larger supply of 
native heat, in order that the aliment may be thoroughly 
concocted and acquire the last degree of perfection, 
they required both lungs and a second ventricle, which 
should force the nutritive fluid through them. 

Every animal that has lungs has therefore two 
ventricles to its heart, one right, another left ; and 
wherever there is a right, there also is there a left 
ventricle ; but the contrary of this does not hold good : 
where there is a left there is not always a right ventricle. 
The left ventricle I call that which is distinct in office, 
not in place from the other, that one namely which 
distributes the blood to the body at large, not to the 
lungs only. Hence the left ventricle seems to form 
the principal part of the heart ; situated in the middle, 
more strongly marked, and constructed with greater 
care, the heart seems formed for the sake of the left 
ventricle, and the right but to minister to it ; for the 
right neither reaches to the apex of the heart, nor is it 
nearly of such strength, being three times thinner in its 
walls, and in some sort jointed on to the left, (as 
Aristotle says ;) though indeed it is of greater capacity, 
inasmuch as it has not only to supply material to the 
left ventricle, but likewise to furnish aliment to the lungs. 

It is to be observed, however, that all this is other- 
wise in the embryo, where there is not such a difference 
between the two ventricles ; but as in a double nut, 
they are nearly equal in all respects, the apex of the 
right reaching to the apex of the left, so that the heart 
presents itself as a sort of double-pointed cone. And 
this is so, because in the foetus, as already said, whilst 
the blood is not passing through the lungs from the 
right to the left cavities of the heart, but flowing by 
the foramen ovale and ductus arteriosus, directly from 
the vena cava into the aorta, whence it is distributed to 

Heart and Blood 99 

the whole body, both ventricles have in fact the same 
office to perform, whence their equality of constitution. 
It is only when the lungs come to be used, and it is 
requisite that the passages indicated should be blocked 
up, that the diflerences in point of strength and other 
things between the two ventricles begin to be apparent : 
in the altered circumstances the right has only to 
throw the blood through the lunus, whilst the left has 
to impel it through the whole body. 

There are further within the heart numerous braces, 
so to speak, fleshy columns and fibrous bands, 
which Aristotle, in his third book on Respiration, and 
the Parts of Animals, entitles nerves. These are 
variously extended, and are either distinct or contained 
in grooves in the walls and partition, where they 
oci ision numerous pits or depressions. They constitute 
a kind of small muscles, which are superadded and 
supplementary to the heart, assisting it to execute a 
more powerful and perfect contraction, and so proving 
subservient to the complete expulsion of the blood. 
They are in some sort like the elaborate and artful 
arrangement of ropes in a ship, bracing the heart on 
every side as it contracts, and so enabling it more 
effectually and forcibly to expel the charge of blood 
from its ventricles. This much is plain, at all events, 
that some animals have them strongly marked, others 
have them less so ; and, in all that have them, they 
are more numerous and stronger in the left than in 
the right ventricle ; and whilst some have them in the 
left, there are yet none present in the right ventricle. 
In the human subject, again, these fleshy columns and 
braces are more numerous in the left than in the right 
ventricle, and they are more abundant in the ventricles 
than in the auricles ; occasionally, indeed, in the 
auricles there appear to be none present whatsoever. 
In large, more muscular and hardier bodies, as of 
countrymen, they are numerous ; in more slender 
frames and in females they are fewer. 

ioo Motion of the 

In those animals in which the ventricles of the heart 
are smooth within, and entirely without fibres or 
muscular bands, or anything like foveas, as in almost 
all the smaller birds, the partridge and the common 
fowl, serpents, frogs, tortoises, and also fishes, for the 
major part, there are no chordae tendineae, nor bundles 
of fibres, neither are there any tricuspid valves in the 

Some animals have the right ventricle smooth 
internally, but the left provided with fibrous bands, 
such as the goose, swan, and larger birds ; and the 
reason here is still the same as elsewhere, as the 
lungs are spongy, and loose, and soft, no great amount 
of force is required to force the blood through them ; 
hence the right ventricle is either without the bundles 
in question, or they are fewer and weaker, not so fleshy 
or like muscles ; those of the left ventricle, however, 
are both stronger and more numerous, more fleshy and 
muscular, because the left ventricle requires to be 
stronger, inasmuch as the blood which it propels has to 
be driven through the whole body. And this, too, 
is the reason why the left ventricle occupies the middle 
of the heart, and has parietes three times thicker and 
stronger than those of the right. Hence all animals — 
and among men it is not otherwise — that are endowed 
with particularly strong frames, and that have large and 
fleshy limbs at a great distance from the heart, have 
this central organ of greater thickness, strength, and 
muscularity. And this is both obvious and necessary. 
Those, on the contrary, that are of softer and more 
slender make have the heart more flaccid, softer, and 
internally either sparely or not at all fibrous. Con- 
sider farther the use of the several valves, which are all 
so arranged, that the blood once received into the 
ventricles of the heart shall never regurgitate, once 
forced into the pulmonary artery and aorta shall not 
flow hack upon the ventricles. When the valves are 
raised and brought together they form a three-cornered 

Heart and Blood 101 

line, such as is left by the bite of a leech ; and the 
more they are forced, the more firmly do they oppose 
the passage of the blood. The tricuspid valves are 
placed, like gate-keepers, at the entrance into the 
ventricles, from the veme cava? and pulmonary veins ; 
lest the blood when most forcibly impelled should flow 
back ; and it is for this reason that they are not found 
in all animals ; neither do they appear to have been 
constructed with equal care in all the animals in which 
they are found ; in some they are more accurately 
fitted, in others more remissly or carelessly contrived, 
and always with a view to their being closed under 
a greater or a slighter force of the ventricle. In the 
left ventricle, therefore, and in order that the occlusion 
may be the more perfect against the greater impulse, 
there are only two valves, like a mitre, and produced 
into an elongated cone, so that they come together and 
touch to their middle ; a circumstance which perhaps 
led Aristotle into the error of supposing this ventricle 
to be double, the division taking place transversely. 
For the same reason, indeed, and that the blood may 
not regurgitate upon the pulmonary veins, and thus the 
force of the ventricle in propelling the blood through 
the system at large come to be neutralized, it is that 
these mitral valves excel those of the right ventricle in 
size and strength, and exactness of closing. Hence, 
too, it is essential that there can be no heart without a 
ventricle, since this must be the source and storehouse 
of the blood. The same law does not hold good in 
reference to the brain. For almost no genus of birds 
has a ventricle in the brain, as is obvious in the goose 
and swan, the brains of which nearly equal that of 
a rabbit in size ; now rabbits have ventricles in the 
brain, whilst the goose has none. In like manner, 
wherever the heart has a single ventricle, there is an 
auricle appended, flaccid, membranous, hollow, filled 
with blood ; and where there are two ventricles, there 
are likewise two auricles. On the other hand, however, 

102 Motion of the 

some animals have an auricle without any ventricle ; or 
at all events they have a sac analogous to an auricle ; 
or the vein itself, dilated at a particular part, performs 
pulsations, as is seen in hornets, bees, and other insects, 
which certain experiments of my own enable me to 
demonstrate have not only a pulse, but a respiration in 
that part which is called the tail, whence it is that this 
part is elongated and contracted now more rarely, now 
more frequently, as the creature appears to be blown 
and to require a larger quantity of air. But of these 
things, more in our Treatise on Respiration. 

It is in like manner evident that the auricles pulsate, 
contract, as I have said before, and throw the blood 
into the ventricles ; so that wherever there is a ventricle 
an auricle is necessary, not merely that it may serve, 
according to the general belief, as a source and maga- 
zine for the blood : for what were the use of its 
pulsations had it nothing to do save to contain ? No ; 
the auricles are prime movers of the blood, especially 
the right auricle, which is " the first to live, the last to 
die," as already said ; whence they are subservient to 
sending the blood into the ventricle, which, contracting 
incontinently, more readily and forcibly expels the 
blood already in motion ; just as the ball-player carr" 
strike the ball more forcibly and further if he takes it 
on the rebound than if he simply threw it. Moreover, 
and contrary to the general opinion, since neither the 
heart nor anything else can dilate or distend itself so as 
to draw aught into its cavity during the diastole, unless 
like a sponge, it has been first compressed, and as it is 
returning to its primary condition ; but in animals all 
local motion proceeds from, and has its original in the 
contraction of some part : it is consequently by the 
contraction of the auricles that the blood is thrown 
into the ventricles, as I have already shown, and from 
thence, by the contraction of the ventricles, it is pro- 
pelled and distributed. Which truth concerning local 
motions, and how the immediate moving organ in 

Heart and Rlood 103 

I v ry motion of an animal primarily endowed with 
a motive spirit (as Aristotle has it, 1 ) is contractile ; and 
in what way the word Kcypov is derived from vivm, nutn, 
contraho ; and how Aristotle was acquainted with the 
muscles, and did not unadvisedly refer all motion in 
animals to the nerves, or to the contractile element, 
and therefore called those little bands in the heart 
nerves — all this, if I am permitted to proceed in my 
purpose of making a particular demonstration of the 
organs of motion in animals from observations in my 
possession, I trust I shall be able to make sufficiently 

But that we may go on with the subject we have in 
hand, viz. the use of the auricles in filling the ventricles : 
we should expect that the more dense and compact the 
heart, the thicker its parietes, the stronger and more 
muscular must be the auricle to force and fill it, and 
vice versa. Now this is actually so : in some the auricle 
presents itself as a sanguinolent vesicle, as a thin mem- 
brane containing blood, as in fishes, in which the sac 
that stands in lieu of the auricle, is of such delicacy 
and ample capacity, that it seems to be suspended or 
to float above the heart ; in those fishes in which the 
sac is somewhat more fleshy, as in the carp, barbel, 
tench, and others, it bears a wonderful and strong 
mblance to the lungs. 

In some men of sturdier frame and stouter make, 
the right auricle is so strong, and so curiously con- 
structed within of bands and variously interlacing fibres, 
that it seems to equal the ventricle of the heart in 
other subjects; and I must say that I am astonished to 
find such diversity in this particular in different in- 
dividuals. It is to be observed, however, that in the 
foetus the auricles are out of all proportion large, which 
is because they are present before the heart [the 
ventricular portion] makes its appearance or suffices for 
its office even when it has appeared, and they therefore 

1 In the book, de Spiritu, and elsewhere. 

104 Motion of the 

have, as it were, the duty of the whole heart committed 
to them, as has already been demonstrated. But what 
I have observed in the formation of the fcetus as 
before remarked (and Aristotle had already confirmed 
all in studying the incubated egg,) throws the greatest 
light and likelihood upon the point. Whilst the fcetus 
is yet in the guise of a soft worm, or, as is commonly 
said, in the milk, there is a mere bloody point or 
pulsating vesicle, a portion apparently of the umbilical 
vein, dilated at its commencement or base ; by and by, 
when the outline of the fcetus is distinctly indicated, 
and it begins to have greater bodily consistence, the 
vesicle in question having become more fleshy and 
stronger, and changed its position, passes into the 
auricles, over or upon which the body of the heart 
begins to sprout, though as yet it apparently performs 
no duty ; but when the fcetus is farther advanced, when 
the bones can be distinguished from the soft parts, and 
movements take place, then it has also a heart inter- 
nately which pulsates, and, as I have said, throws 
blood by either ventricle from the vena cava into the 
"*> Thus nature, ever perfect and divine, doing nothing 
in vain, has neither given a heart where it was not 
required, nor produced it before its office had become 
necessary ; but by the same stages in the development 
of every animal, passing through the constitutions of 
all, as I may say (ovum, worm, fcetus), it acquires 
perfection in each. These points will be found else- 
where confirmed by numerous observations on the 
formation of the fcetus. 

Finally, it was not without good grounds that Hippo- 
crates, in his book, " De Corde," intitles it a muscle ; as 
its action is the same, so is its function, viz. to con- 
tract and move something else, in this case, the charge 
of blood. 

Farther, as in muscles at large, so can we infer the 
action and use of the heart from the arrangement of its 

Heart and Blood 105 

fibres and its general structure. All anatomists admit 
with Galen that the body of the heart is made up of 
various courses of fibres running straight, obliquely, 
and transversely, with reference to one another; but 
in a heart which has been boiled the arrangement of 
the til ires is seen to be different : all the fibres in the 
parietes and septum are circular, as in the sphincters ; 
those, again, which are in the columnar extend length- 
wise, and are oblique longitudinally; and so it comes 
to pass, that when all the fibres contract simultaneously, 
the apex of the cone is pulled towards its base by the 
columnar, the walls are drawn circularly together into a 
globe, the whole heart in short is contracted, and the 
ventricles narrowed ; it is therefore impossible not to 
perceive that, as the action of the organ is so plainly 
contraction, its function is to propel the blood into the 

Nor are we the less to agree with Aristotle in regard 
to the sovereignty of the heart , nor are we to inquire 
whether it receives sense and motion from the brain ? 
whether blood from the liver ? whether it be the origin 
of the veins and of the blood? and more of the same 
description. They who affirm these propositions against 
Aristotle, overlook, or do not rightly understand the 
principal argument, to the effect that the heart is the 
first part which exists, and that it contains within itself 
blood, life, sensation, motion, before either the brain 
or the liver were in being, or had appeared distinctly, 
or, at all events, before they could perform any function. 
The heart, ready furnished with its proper organs of 
motion, like a kind of internal creature, is of a date 
anterior to the body : first formed, nature willed that it 
should afterwards fashion, nourish, preserve, complete 
the entire animal, as its work and dwelling place : the 
heart, like the prince in a kingdom, in whose hands lie 
the chief and highest authority, rules over all ; it is the 
original and foundation from which all power is derived, 
on which all power depends in the animal body. 

io6 Motion of the 

And many things having reference to the arteries 
farther illustrate and confirm this truth. Why does 
not the arteria venosa pulsate, seeing that it is num- 
bered among the arteries ? Or wherefore is there a 
pulse in the vena arteriosa ? Because the pulse of the 
arteries is derived from the impulse of the blood. 
Why does an artery differ so much from a vein in 
the thickness and strength of its coats ? Because it 
sustains the shock of the impelling heart and streaming 
blood. Hence, as perfect nature does nothing in vain, 
and suffices under all circumstances, we find that the 
nearer the arteries are to the heart, the more do they 
differ from the veins in structure ; here they are both 
stronger and more ligamentous, whilst in extreme parts 
of the body, such as the feet and hands, the brain, the 
mesentery, and the testicles, the two orders of vessels 
are so much alike that it is impossible to distinguish 
between them with the eye. Now this is for the 
following very sufficient reasons : for the more remote 
vessels are from the heart, with so much the less force 
are they impinged upon by the stroke of the heart, 
which is broken by the great distance at which it is 
given. Add to this, that the impulse of the heart 
exerted upon the mass of blood, which must needs 
fill the trunks and branches of the arteries, is diverted, 
divided, as it were, and diminished at every sub- 
division ; so that the ultimate capillary divisions of 
the arteries look like veins, and this not merely in 
constitution but in function ; for they have either no 
perceptible pulse, or they rarely exhibit one, and never 
save where the heart beats more violently than wont, 
or at a part where the minute vessel is more dilated or 
open than elsewhere. Hence it happens that at times 
we are aware of a pulse in the teeth, in inflammatory 
tumours, and in the fingers ; at another time we feel 
nothing of the sort. Hence, too, by this single symptom 
I have ascertained for certain that young persons, 
whose pulses are naturally rapid, were labouring under 

Heart and Blood 107 

fever ; in like manner, on compressing the fingers in 
youthful and delicate subjects during a feeble paroxysm, 
I have readily perceived the pulse there. On the other 
hand, when the heart pulsates more languidly, it is 
often impossible to feel the pulse not merely in the 
fingers, but at the wrist, and even at the temple ; this 
is the case in persons afflicted with lipothymiae and 
asphyxia, and hysterical symptoms, as also in persons 
of very weak constitution and in the moribund. 

And here surgeons are to be advised that, when the 
blood escapes with force in the amputation of limbs, in 
the removal of tumours, and in wounds, it constantly 
comes from an artery ; not always per saltum, however, 
rose the smaller arteries do not pulsate, especially 
if a tourniquet has been applied. 

And then the reason is the same wherefore the 
pulmonary artery has not only the structure of an 
artery, but wherefore it does not differ so widely in 
the thickness of its tunics from the veins as the aorta : 
the aorta sustains a more powerful shock from the left 
ventricle than the pulmonary artery does from the 
right ; and the tunics of this last vessel are thinner 
and softer than those of the aorta in the same pro- 
portion as the walls of the right ventricle of the heart 
are weaker and thinner than those of the left ventricle ; 
and in like manner, in the same degree in which the 
lungs are softer and iaxer in structure than the flesh 
and other constituents of the body at large, do the 
tunics of the branches of the pulmonary artery differ 
from the tunics of the vessels derived from the aorta. 
And the same proportion in these several particulars 
is universally preserved. The more muscular and 
powerful men are, the firmer their flesh, the stronger, 
thicker, denser, and more fibrous their heart, in the 
same proportion are the auricles and arteries in all 
respects thicker, closer, and stronger. And again, and 
on the other hand, in those animals the ventricles of 
whose heart are smooth within, without villi or valves, 

108 Motion of the Heart and Blood 

and the walls of which are thinner, as in fishes, 
serpents, birds, and very many genera of animals, in 
all of them the arteries differ little or nothing in the 
thickness of their coats from the veins. 

Farther, the reason why the lungs have such ample 
vessels, both arteries and veins, (for the capacity of the 
pulmonary veins exceeds that of both the crural and 
jugular vessels,) and why they contain so large a 
quantity of blood, as by experience and ocular in- 
spection we know they do, admonished of the fact 
indeed by Aristotle, and not led into error by the 
appearances found in animals which have been bled 
to death, — is, because the blood has its fountain, and 
storehouse, and the workshop of its last perfection in 
the heart and lungs. Why, in the same way we find in 
the course of our anatomical dissections the arteria 
venosa and left ventricle so full of blood, of the same 
black colour and clotted character, too, as that with 
which the right ventricle and pulmonary artery are filled, 
inasmuch as the blood is incessantly passing from one 
side of the heart to the other through the lungs. 
Wherefore, in fine, the pulmonary artery or vena 
arteriosa has the constitution of an artery, and the 
pulmonary veins or arterise venosse have the structure 
of veins ; because, in sooth, in function and constitu- 
tion, and everything else, the first is an artery, the 
others are veins, in opposition to what is commonly 
believed ; and why the pulmonary artery has so large 
an orifice, because it transports much more blood than 
is requisite for the nutrition of the lungs. 

All these appearances, and many others, to be noted 
in the course of dissection, if rightly weighed, seem 
clearly to illustrate and fully to confirm the truth con- 
tended for throughout these pages, and at the same 
time to stand in opposition to the vulgar opinion ; for 
it would be very difficult to explain in any other way to 
what purpose all is constructed and arranged as we 
have seen it to be. 





JOHN RIOLAN, Jun., OF Paris 








Cambridge, 1649. 



Some few months ago there appeared a small 
anatomical and pathological work from the pen of the 
celebrated Riolanus, for which, as sent to me by the 
author himself, I return him my grateful thanks. 1 I 
also congratulate this author on the highly laudable 
undertaking in which he has engaged. To demonstrate 
the seats of all diseases is a task that can only be 
achieved under favour of the highest abilities ; for 
surely he enters on a difficult province who proposes 
to bring under the cognizance of the eyes those 
diseases which almost escape the keenest understand- 
ing. But such efforts become the prince of anatomists ; 
for there is no science which does not spring from 
preexisting knowledge, and no certain and definite idea 
which has not derived its origin from the senses. 
Induced therefore by the subject itself, and the example 
of so distinguished an individual, which makes me 
think lightly of the labour, I also intend putting to 
press my Medical Anatomy, or Anatomy in its Appli- 
cation to Medicine. Not with the purpose, like 
Riolanus, of indicating the seats of diseases from the 
bodies of healthy subjects, and discussing the several 
diseases that make their appearance there, according 
to the views which others have entertained of them ; 
but that I may relate from the many dissections I have 

1 Enchiridium Anatomicum et Pathologicum. i2ino, Parisiis, 1648. 


ii2 Circulation of the Blood 

made of the bodies of persons diseased, worn out by 
serious and strange affections, how and in what way 
the internal organs were changed in their situation, 
size, structure, figure, consistency, and other sensible 
qualities, from their natural forms and appearances, 
such as they are usually described by anatomists; and 
in what various and remarkable ways they were affected. 
For even as the dissection of healthy and well-con- 
stituted bodies contributes essentially to the advance- 
ment of philosophy and sound physiology, so does the 
inspection of diseased and cachectic subjects power- 
fully assist philosophical pathology. And, indeed, the 
physiological consideration of the things which are 
according to nature is to be first undertaken by medical 
men ; since that which is in conformity with nature 
is right, and serves as a rule both to itself and to that 
which is amiss ; by the light it sheds, too, aberrations 
and affections against nature are defined ; pathoiogy 
then stands out more clearly ; and from pathology the 
use and art of healing, as well as occasions for the 
discovery of many new remedies, are perceived. Nor 
could any one readily imagine how extensively internal 
organs are altered in diseases, especially chronic dis- 
eases, and what monstrosities among internal parts 
these diseases engender. So that I venture to say, 
that the examination of a single body of one who has 
died of tabes or some other disease of long standing, 
or poisonous nature, is of more service to medicine 
than the dissection of the bodies of ten men who have 
been hanged. 

I would not have it supposed by this that I in any 
way disapprove of the purpose of Riolanus, that learned 
and skilful anatomist; on the contrary, I think it 
deserving of the highest praise, as likely to be ex- 
tremely useful to medicine, inasmuch as it illustrates 
the physiological branch of this science ; but I have 
thought that it would scarcely turn out less profitable 
to the art of healing, did I place before the eyes of 

Circulation of the Blood 113 

my readers not only the places, but the affections of 
these places, illustrating them as I proceed with obser- 
vations, and recording the results of my experience 
derived from my numerous dissections. 

Rut it is imperative on me first to dispose of those 
observations contained in the work referred to, which 
beat upon the circulation of the blood as discovered 
by me, and which seem to require especial notice at 
my hands. For the judgment of such a man, who is 
indeed the prince and leader of all the anatomists of 
the present age, in such a matter, is not to be lightly 
esteemed, but is rather to be held of greater weight 
and authority, either for praise or blame, than the 
commendations or censure of all the world besides. 

Riolanus, then, admits our motion of the blood in 
animals, 1 and falls in with our conclusions in regard 
to the circulation ; yet not entirely and avowedly ; for 
he says 2 that the blood contained in the vena portre 
does not circulate like that in the vena cava; and 
again he states 3 that there is some blood which cir- 
culates, and that the circulatory vessels are the aorta 
and vena cava; but then he denies that the continua- 
tions of these trunks have any circulation, " because 
the blood is effused into all the parts of the second 
and third regions, where it remains for purposes of 
nutrition ; nor does it return to any greater vessels, 
unless forcibly drawn back when there is a great lack 
of blood in the main channels, or driven by a fit of 
passion when it flows to the greater circulatory vessels ; " 
and shortly afterwards : " thus, as the blood of the 
veins naturally ascends incessantly or returns to the 
heart, so the blood of the arteries descends or departs 
from the heart ; still, if the smaller veins of the arms 
and legs be empty, the blood filling the empty channels 
in succession, may descend in the veins, as I have 

1 Enchiridion, lib. iii, cap. 8. 

* lb. lib. ii, cap 21. 

• lb. lib. iii, cap. 8. 

K 262 

ii4 Circulation of the Blood 

clearly shown," he says, "against Harvey and Walaeus." 
And as the authority of Galen and daily experience 
confirm the anastomoses of the arteries and veins, and 
the necessity of the circulation of the blood, " you 
perceive." he continues, " how the circulation is effected, 
without any perturbation or confusion of fluids and the 
destruction of the ancient system of medicine." 

These words explain the motives by which this 
illustrious anatomist was actuated when he was led 
partly to admit, partly to deny the circulation of the 
blood; and why he only ventures on an undecided 
and inconclusive opinion of the subject ; his fear is 
lest it destroy the ancient medicine. Not yielding 
implicitly to the truth, which it appears he could not 
help seeing, but rather guided by caution, he fears 
speaking plainly out, lest he offend the ancient physic, 
or perhaps seem to retract the physiological doctrines 
he supports in his Anthropology. The circulation of 
the blood does not shake, but much rather confirms 
the ancient medicine ; though it runs counter to the 
physiology of physicians, and their speculations upon 
natural subjects, and opposes the anatomical doctrine 
of the use and action of the heart and lungs, and rest 
of the viscera. That this is so shall readily be made 
to appear, both from his own words and avowal, and 
partly also from what I shall supply ; viz. that the 
whole of the blood, wherever it be in the living body, 
moves and changes its place, not merely that which is 
in the larger vessels and their continuations, but that 
also which is in their minute subdivisions, and which 
is contained in the pores or interstices of every part ; 
that it flows from and back to the heart ceaselessly 
and without pause, and could not pause for ever so 
short a time without detriment, although I admit that 
occasionally, and in some places, its motion is quicker 
or slower. 1 

In the first place, then, our learned anatomist only 

1 Vide Chapter III. 

Circulation of the Blood 1 1 


denies that the contents of the branches in continuation 
of the vena portae circulate ; but he could neither 
oppose nor deny this, did he not conceal from himself 
the force of his own arguments ; for he says in his 
Third Book, chap, viii., "If the heart at each pulsa- 
tion admits a drop of blood which it throws into the 
aorta, and in the course of an hour makes two thousand 
beats, it is a necessary consequence that the quantity 
of blood transmitted must be great." He is farther 
forced to admit as much in reference to the mesentery, 
when he sees that far more than single drops of blood 
are sent into the coeliac and mesenteric arteries at 
each pulsation ; so that there must either be some 
outlet for the fluid, of magnitude commensurate with 
its quantity, or the branches of the vena portae must 
give way. Nor can the explanation that is had recourse 
to with a view of meeting the difficulty, viz. that the 
blood of the mesentery ebbs and flows by the same 
channels, after the manner of Euripus, be received as 
either probable or possible. Neither can the reflux 
from the mesentery be effected by those passages and 
that system of translation, by which he will have it to 
disgorge itself into the aorta; this were against the 
force of the existing current, and by a contrary motion ; 
nor can anything like pause or alternation be admitted, 
where there is very certainly an incessant influx : the 
blood sent into the mesentery must as inevitably go 
elsewhere as that which is poured into the heart. And 
this is obvious ; were it otherwise, indeed, everything 
like a circulation might be overturned upon the same 
showing and by the same subterfuge ; it might just as 
well be said that the blood contained in the left 
ventricle of the heart is propelled into the aorta during 
the systole, and flows back to it during the diastole, 
the aorta disgorging itself into the ventricle, precisely 
as the ventricle has disgorged itself into the aorta. 
There would thus be circulation neither in the heart 
nor in the mesentery, but an alternate flux and reflux, — 

n6 Circulation of the Blood 

a useless labour, as it seems. If, therefore, and for the 
reason assigned and approved by him, a circulation 
through the heart be argued for as a thing necessary, 
the argument has precisely the same force when applied 
to the mesentery : if there be no circulation in the 
mesentery, neither is there any in the heart ; for both 
affirmations, this in reference to the heart, that in 
reference to the mesentery, merely changing the words, 
stand or fall together, by force of the very same 

He says : "The sigmoid valves prevent regurgitation 
into the heart ; but there are no valves in the mesentery." 
To this I reply, that the thing is not so ; for there is a 
valve in the splenic vein, and sometimes also in other 
veins. And besides, valves are not met with universally 
in veins ; there are few or none in the deep-seated 
veins of the extremities, but many in the subcutaneous 
branches. For where the blood is flowing naturally 
from smaller into greater branches, into which it is 
disposed to enter, the pressure of the circumjacent 
muscles is enough, and more than enough to prevent 
all retrograde movement, and it is forced on where the 
way lies open ; in such circumstances, what use were 
there for valves ? But the quantity of blood that is 
forced into the mesentery by each stroke of the heart, 
may be estimated in the same way as you estimate the 
quantity impelled into the hand when you bind a 
ligature with medium tightness about the wrist : if in so 
many beats the vessels of the hand become distended, 
and the whole extremity swells, you will find, that much 
more than a single drop of blood has entered with each 
pulse, and which cannot return, but must remain to fill 
the hand and increase its size. But analogy permits 
us to say, that the same thing takes place in reference 
to the mesentery and its vessels, in an equal degree at 
least, if not in a greater degree, seeing that the vessels 
of the mesentery are considerably larger than those of 
the carpus. And if any one will but think on the 

Circulation of the Blood 117 

difficulty that is experienced with all the aid supplied 
by compresses, bandages, and a multiplied apparatus, 
in restraining the flow of blood from the smallest 
artery when wounded, with what force it overcomes all 
obstacles and soaks through the whole apparatus, he 
will scarcely, I imagine, think it likely that there can 
be any retrograde motion against such an impulse and 
influx of blood, any retrograde force to meet and over- 
come a direct force of such power. Turning over these 
things in his mind, I say, no one will ever be brought 
to believe that the blood from the branches of the 
vena porta; can possibly make its way by the same- 
channels against an influx by the artery of such 
impetuosity and force, and so unload the mesentery. 

Moreover, if the learned anatomist does not think 
that the blood is moved and changed by a circular 
motion, but that the same fluid always stagnates in the 
channels of the mesentery, he appears to suppose that 
there are two descriptions of blood, serving different 
uses and ends ; that the blood of the vena portae, and 
that of the vena cava are dissimilar in constitution, 
seeing that the one requires a circulation for its 
preservation, the other requires nothing of the kind ; 
which neither appears on the face of the thing, nor is its 
truth demonstrated by him. Our author then refers 
to " A fourth order of mesenteric vessels, the lacteal 
vessels, discovered by Asellius," x and having mentioned 
these, he seems to infer that they extract all the 
nutriment from the intestines, and transfer this to the 
liver, the workshop of the blood, whence, having been 
concocted and changed into blood, (so he says in his 
third book, chapter the 8th), the blood is transferred 
from the liver to the right ventricle of the heart. 
" Which things premised," he continues, 2 " all the 
difficulties which were formerly experienced in regard 
to the distribution of the chyle and blood by the same 
channel come to an end; for the lacteal veins cany 

1 Enchiridion, lib. ii, cap. 18. * Ibid. 

n8 Circulation of the Blood 

the chyle to the liver, and as these canals are distinct, 
so may they be severally obstructed." But truly I 
would here ask : how this milky fluid can be poured 
into and pass through the liver, and how from thence 
gain the vena cava and the ventricle of the heart 
when our author denies that the blood of the vena 
porta? passes through the liver, and that so a circulation 
is established ? I pause for a reply. I would fain 
know how such a thing can be shown to be probable ; 
especially when the blood appears to be both more 
spirituous or subtile and penetrating than the chyle or 
milk contained in these lacteal vessels, and is further 
impelled by the pulsations of the arteries that it may 
find a passage by other channels. 

Our learned author mentions a certain tract of his 
on the Circulation of the Blood : I wish I could 
obtain a sight of it ; perhaps I might retract. But had 
the learned writer been so disposed, I do not see but 
that having admitted the circular motion of the blood, 1 
all the difficulties which were formerly felt in connexion 
with the distribution of the chyle and the blood by the 
same channels are brought to an equally satisfactory 
solution ; so much so indeed that there would be no 
necessity for inquiring after or laying down any separate 
vessels for the chyle. Even as the umbilical veins 
absorb the nutritive juices from the fluids of the egg 
and transport them for the nutrition and growth of the 
chick, in its embryo state, so do the meseraic veins 
suck up the chyle from the intestines and transfer it to 
the liver ; and why should we not maintain that they 
perform the same office in the adult ? For all the 
mooted difficulties vanish when we cease to suppose 
two contrary motions in the same vessels, and admit 
but one and the same continuous motion in the 
mesenteric vessels from the intestines to the liver. 

1 Enchiridion, lib. iii, cap. 8 : " The blood incessantly and naturally 
ascends or flows back to the heart in the veins, as jn the ^ arteries it 
descends or departs from the heart." 

Circulation of the Blood jiq 

I shall elsewhere state my views of the lacteal veins 
when I treat of the milk found in different parts of 
new-born animals, especially of the human subject j 
for it is met with in the mesentery and all its gland . 
in the thymus, in the axillae, also in the breasts of 
infants. This milk the midwifes are in the habit of 
pressing out, for the health, as they believe, of the 
infants. But it has pleased the learned Riolanus, not 
only to take away circulation from the blood contained 
in the mesentery ; he affirms that neither do the vessels 
in continuation of the vena cava, nor the arteries, nor 
any of the parts of the second and third regions, admit 
of circulation, so that he entitles and enumerates as 
circulating vessels the vena cava and aorta only. For 
this he appears to me to give a very indifferent reason : l 
" The blood," he says, " effused into all the parts of the 
second and third regions, remains there for their 
nutrition ; nor does it return to the great vessels, unless 
forcibly drawn back by an extreme dearth of blood in 
the great vessels, nor, unless carried by an impulse, 
does it flow to the circulatory vessels." 

That so much of the blood must remain as is 
appropriated to the nutrition of the tissues, is matter 
of necessity ; for it cannot nourish unless it be 
assimilated and become coherent, and form substance 
in lieu of that which is lost ; but that the whole of the 
blood which flows into a part should there remain, in 
order that so small a portion should undergo transforma- 
tion, is nowise necessary ; for no part uses so much blood 
for its nutrition as is contained in its arteries, veins, 
and interstices. Nor because the blood is continually 
coming and going is it necessary to suppose that it 
leaves nothing for nutriment behind it. Consequently 
it is by no means necessary that the whole remain in 
order that nutrition be effected. But our learned 
author, in the same book, where he affirms so much, 
appears almost everywhere else to assert the contrary. 

1 Enchirid. lib. iii, cap 8. 

120 Circulation of the Blood 

In that paragraph especially where he describes the 
circulation in the brain, he says : " And the brain by 
means of the circulation sends back blood to the heart, 
and thus refrigerates the organ." And in the same 
way are all the more remote parts said to refrigerate 
the heart ; thus in fevers, when the praecordia are 
scorched and burn with febrile heat, patients baring 
their limbs and casting off the bedclothes, seek to cool 
their heart; and the blood generally, tempered and 
cooled down, as our learned author states it to be with 
reference to the brain in particular, returns by the 
veins and refrigerates the heart. Our author, therefore, 
appears to insinuate a certain necessity for a circulation 
from every part, as well as from the brain, in opposition 
to what he had before said in very precise terms. But 
then he cautiously and ambiguously asserts, that the 
blood does not return from the parts composing the 
second and third regions, unless, as he says, it is drawn 
by force, and through a signal deficiency of blood in 
the larger vessels, &c, which is most true if these 
words be rightly understood ; for by the larger vessels, 
in which the deficiency is said to cause the reflux, I 
think he must be held to mean the veins not the 
arteries ; for the arteries are never emptied, save into 
the veins or interstices of parts, but are incessantly 
filled by the strokes of the heart ; but in the vena cava 
and other returning channels, in which the blood glides 
rapidly on, hastening to the heart, there would speedily 
be a great deficiency of blood did not every part 
incessantly restore the blood that is incessantly poured 
into it. Add to this, that by the impulse of the 
blood which is forced with each stroke into every 
part of the second and third regions, that which is 
contained in the pores or interstices is urged into the 
smaller veins, from which it passes into larger vessels, 
its motion assisted besides by the motion and pressure 
of circumjacent parts ; for from every containing thing 
compressed and constringed, contained matters are 

Circulation of the Blood 121 

forced out. And thus it is that by the motions of the 
muscles and extremities, the blood contained in the 
minor vessels is forced onwards and delivered into 
the larger trunks. But that the blood is incessantly driven 
from the arteries into every part of the body, there gives 
a pulse and never flows back in these channels, cannot 
be doubted, if it be admitted that with each pulse of 
the heart all the arteries are simultaneously distended 
by the blood sent into them ; and as our learned 
author himself allows that the diastole of the arteries is 
usioned by the systole of the heart, and that the 
blood once out of the heart can never get back into 
the ventricles by reason of the opposing valves ; if I 
say, our learned author believes that these things are 
so, it will be as manifestly true with regard to the force 
and impulse by which the blood contained in the 
vessels is propelled into every part of every region of 
the body. For wheresoever the arteries pulsate, so far 
must the impulse and influx extend, and therefore is the 
impulse felt in every part of each several region ; for 
there is a pulse everywhere, to the very points of the 
fingers and under the nails, nor is there any part of 
the body where the shooting pain that accompanies 
each pulse of the artery, and the effort made to effect 
a solution of the continuity is not experienced when it 
is the seat of a phlegmon or furuncle. 

But, further, that the blood contained in the pores of 
the living tissues returns to the heart, is manifest from 
what we observe in the hands and feet. For we 
frequently see the hands and feet, in young persons 
especially, during severe weather, become so cold that 
to the touch they feel like ice, and they are so be- 
numbed and stiffened that they seem scarcely to retain 
a trace of sensibility or to be capable of any motion ; 
still are they all the while surcharged with blood, and 
look red or livid. Yet can the extremities be warmed 
in no way, save by circulation ; the chilled blood, which 
has lost its spirit and heat, being driven out, and fresh, 

122 Circulation of the Blood 

warm, and vivified blood flowing in by the arteries in 
its stead, which fresh blood cherishes and warms the 
parts, and restores to them sense and motion ; nor 
could the extremities be restored by the warmth of a 
fire or other external heat, any more than those of 
a dead body could be so recovered : they are only 
brought to life again, as it were, by an influx of internal 
warmth. And this indeed is the principal use and end 
of the circulation ; it is that for which the blood is sent 
on its ceaseless course, and to exert its influence con- 
tinually in its circuit, to wit, that all parts dependent 
on the primary innate heat may be retained alive, in 
their state of vital and vegetative being, and apt to 
perform their functions ; whilst, to use the language of 
physiologists, they are sustained and actuated by the 
inflowing heat and vital spirits. Thus, by the aid of 
two extremes, viz. cold and heat, is the temperature of 
the animal body retained at its mean. For as the air 
inspired tempers the too great heat of the blood in the 
lungs and centre of the body, and effects the expulsion 
of suffocating fumes, so in its turn does the hot blood, 
thrown by the arteries into all parts of the body, cherish 
and nourish and keep them in life, defending them 
from extinction through the power of external cold. 

It would, therefore, be in some sort unfair and extra- 
ordinary did not every particle composing the body 
enjoy the advantages of the circulation and transmuta- 
tion of the blood ; the ends for which the circulation 
was mainly established by nature would no longer be 
effected. To conclude then : you see how circulation 
may be accomplished without confusion or admixture 
of humours, through the whole body, and each of its 
individual parts, in the smaller as well as in the larger 
vessels ; and all as matter of necessity and for the 
general advantage ; without circulation, indeed, there 
would be no restoration of chilled and exhausted parts, 
no continuance of these in life ; since it is apparent 
enough that the whole influence of the preservative 

Circulation d\ the Mood 123 

heat comes by the arteries, and is the work of the 

It, therefore, appears to me that the learned Riolanus 
sp aks rather expediently than truly, when in his 
Enchiridion he denies a circulation to certain parts ; it 
would seem as though he had wished to please the 
mass, and oppose none ; to have written with such a 
bias rather than rigidly and in behalf of the simple 
truth. This is also apparent when he would have the 
blood to make its way into the left ventricle through 
the septum of the heart, by certain invisible and un- 
known passages, rather than through those ample and 
abundantly pervious channels, the pulmonary vessels, 
furnished with valves, opposing all reflux or regurgita- 
tion. He informs us that he has elsewhere discussed 
the reasons of the impossibility or inconvenience of 
this : I much desire to see his disquisition. It would 
be extraordinary, indeed, were the aorta and pulmonary 
artery, with the same dimensions, properties, and 
structure, not to have the same functions. But it would 
be more wonderful still were the whole tide of the blood 
to reach the left ventricle by a set of inscrutable passages 
of the septum, a tide which, in quantity, must corres- 
pond, first to the influx from the vena cava into the 
right side of the heart, and next to the efflux from the 
left, both of which require, such ample conduits. But 
our author has adduced these matters inconsistently, 
for he has established the lungs as an emunctory or 
passage from the heart ; x and he says : " The lung is 
affected by the blood which passes through it, the 
sordes flowing along with the blood." And, again : 
"The lungs receive injury from distempered and ill- 
conditioned viscera ; these deliver an impure blood to 
the heart, which it cannot correct except by multiplied 
circulations." In the same place, he further proceeds, 
whilst speaking against Galen of blood-letting in peri- 
pneumonia and the communication of the veins : 

' Lib. iii, cap. 6. 

124 Circulation of the Blood 

Were it true that the blood naturally passed from the 
right ventricle of the heart to the lungs, that it might 
be carried into the left ventricle and from thence into 
the aorta; and were the circulation of the blood 
admitted, who does not see that in affections of the 
lungs the blood would flow to them in larger quantity 
and would oppress them, unless it were taken away, 
first, freely, and then in repeated smaller quantities in 
order to relieve them, which indeed was the advice of 
Hippocrates, who, in affections of the lungs takes away 
blood from every part — the head, nose, tongue, arms 
and feet, in order that its quantity may be diminished 
and a diversion effected from the lungs ; he takes away 
blood till the body is almost bloodless. Now admitting 
the circulation, the lungs are most readily depleted by 
opening a vein ; but rejecting it, I do not see how any 
revulsion of the blood can be accomplished by this 
means ; for did it flow back by the pulmonary artery 
upon the right ventricle, the sigmoid valves would 
oppose its entrance, and any escape from the right 
ventricle into the vena cava is prevented by the 
tricuspid valves. The blood, therefore, is soon 
exhausted when a vein is opened in the arm or foot, if 
we admit the circulation ; and the opinion of Fernelius 
is at the same time upset by this admission, viz. that in 
affections of the lungs it is better to bleed from the 
right than the left arm ; because the blood cannot flow 
backwards into the vena cava unless the two barriers 
situated in the heart be first broken down." 

He adds yet further in the same place i 1 "If the 
circulation of the blood be admitted, and it be acknow- 
ledged that this fluid generally passes through the lungs, 
not through the middle partition of the heart, a double 
circulation becomes requisite ; one effected through the 
lungs, in the course of which the blood quitting the 
right ventricle of the heart passes through the lungs in 
order that it may arrive at the left ventricle; leaving 

1 Lib. iii, cap. 6. 

Circulation of the Blood 125 

the heart on the one hand, therefore, the blood 
speedily returns to it again ; another and longer circula- 
tion proceeding from the left ventricle of the heart 
performs the circuit of the whole body by the arteries, 
and by the veins returns to the right side of the heart." 

The learned anatomist might here have added a third 
and extremely short circulation, viz. from the left to the 
right ventricle of the heart, with that blood which 
courses through the coronary arteries and veins, and by 
their ramifications is distributed to the body, walls, and 
septum of the heart. 

" He who admits one circulation," proceeds our 
author, " cannot repudiate the other;" and he might, 
as it appears, have added, "the third." For why 
should the coronary arteries of the heart pulsate, if it 
were not to force on the blood by their pulsations ? 
and why should there be coronary veins, the end and 
office of all veins being to receive the blood brought by 
the arteries, were it not to deliver and discharge the 
blood sent into the substance of the heart? In this 
consideration let it be remembered that a valve is very 
commonly found at the orifice of the coronary vein, 
as our learned author himself admits, 1 preventing all 
ingress, but offering no obstacle to the egress of the 
blood. It therefore seems that he cannot do otherwise 
than admit this third circulation, who acknowledges a 
general circulation through the body, and that the 
blood also passes through the lungs and the brain. 2 
Nor, indeed, can he deny a similar circulation to every 
other part of every other region. The blood flowing 
in under the influence of the arterial pulse, and returning 
by the veins, every particle of the body has its 

From the words of our learned writer quoted above, 
consequently, his opinion may be gathered both of the 
general circulation, and then of the circulation through 
the lungs and the several parts of the body ; for he who 

1 Lib. iii, cap. 9. * Lib. iv, cap. 2. 

126 Circulation of the Blood 

admits the first, manifestly cannot refuse to acknow- 
ledge the others. How indeed could he who has 
repeatedly asserted a circulation through the general 
system and the greater vessels, deny a circulation in 
the branches continuous with these vessels, or in the 
several parts of the second and third regions? as if all 
the veins, and those he calls greater circulatory vessels, 
were not enumerated by every anatomist, and by him- 
self, as being within the second region of the body. Is 
it possible that there can be a circulation which is 
universal, and which yet does not extend through every 
part ? Where he denies it, then, he does so hesitatingly, 
and vacillates between negations, giving us mere words. 
Where he asserts the circulation, on the contrary, he 
speaks out heartily, and gives sufficient reasons, as 
becomes a philosopher; and then, when he relies on 
this opinion in a particular instance, he delivers himself 
like an experienced physician and honest man, and, in 
opposition to Galen and his favourite Femelius, advises 
blood-letting as the chief remedy in dangerous diseases 
of the lungs. 

No learned man and Christian, having doubts in such 
a cause, would have recommended his experience to 
posterity, to the imminent risk, and even loss of human 
life ; neither would he, without very sufficient reasons, 
have repudiated the authority of Galen and Femelius, 
which has usually such weight with him. Whatever he 
has denied in the circulation of the blood, therefore, 
whether with reference to the mesentery or any other 
part, and with an eye to the lacteal veins or the ancient 
system of physic, or any other consideration, must be 
ascribed to his courtesy and modesty, and is to be 

Thus far, I think, it appears plain enough, from the 
very words and arguments of our author, that there is a 
circulation everywhere ; that the blood, wherever it is, 
changes its place, and by the veins returns to the heart ; 
so that our learned author seems to be of the same 

Circulation of the Blood 127 

opinion as myself. It would therefore be labour in 
vain, did I here quote at greater length the various 
reasons which I have consigned in my work on th 
Motion of the Blood, in confirmation of my opinions, 

and which are derived from the structure of the vessels, 
the position of the valves, and other matters of ex- 
perience and observation ; and this the more, as I have 
not yet seen the treatise on the Circulation of the Blood 
of the learned writer; nor, indeed, have I yet met with 
a single argument of his, or more than his simple 
negation, which would lead me to see wherefore he 
should reject a circulation which he admits as universal, 
in certain parts, regions, and vessels. 

It is true that by way of subterfuge he has recourse 
to an ana>tomosis of the vessels on the authority of 
Galen, and the evidence of daily experience. But so 
distinguished a personage, an anatomist so expert, 
so inquisitive, and careful, should first have shown 
anastomoses between the larger arteries and larger 
veins, and these, both obvious and ample, having 
mouths in relation with such a torrent as is constituted 
by the whole mass of the blood, and larger than the 
capacity of the continuous branches, (from which he 
takes away all circulation,) before he had rejected 
those that are familiarly known, that are more likely 
and more open ; he ought to have clearly shown us 
where these anastomoses are, and how they are 
fashioned, whether they be adapted only to permit 
the access of the blood into the veins, and not to allow 
of its regurgitation, in the same way as we see the 
ureters connected with the urinary bladder, or in what 
other manner things are contrived. But — and here I 
speak over boldly perhaps — neither our learned author 
himself, nor Galen, nor any experience, has ever suc- 
ceeded in making such anastomoses as he imagines, 
sensible to the eye. 

I have myself pursued this subject of the anastomosis 
with all the diligence I could command, and have given 

128 Circulation of the Blood 

not a little both of time and labour to the inquiry ; but 
I have never succeeded in tracing any connexion be- 
tween arteries and veins by a direct anastomosis of 
their orifices. I would gladly learn of those who give 
so much to Galen, how they dare swear to what he 
says. Neither in the liver, spleen, lungs, kidneys, nor 
any other viscus, is such a thing as an anastomosis to 
be seen ; and by boiling, I have rendered the whole 
parenchyma of these organs so friable that it could be 
shaken like dust from the fibres, or picked away with a 
needle, until I could trace the fibres of every sub- 
division, and see every capillary filament distinctly. 
I can therefore boldly affirm, that there is neither any 
anastomosis of the vena portae with the cava, of the 
arteries with the veins, or of the capillary ramifications 
of the biliary ducts, which can be traced through the 
entire liver, with the veins. This alone may be observed 
in the recent liver : all the branches of the vena cava 
ramifying through the convexity of the liver, have their 
tunics pierced with an infinity of minute holes as is a 
sieve, and are fashioned to receive the blood in its 
descent. The branches of the porta are not so con- 
stituted, but simply spread out in subdivisions ; and the 
distribution of these two vessels is such, that whilst 
the one runs upon the convexity, the other proceeds 
along the concavity of the liver to its outer margin, and 
all the while without anastomosing. 

In three places only do I find anything that can be 
held equivalent to an anastomosis. From the carotids, 
as they are creeping over the base of the brain, 
numerous interlaced fibres arise, which afterwards form 
the choroid plexus, and passing through the lateral 
ventricles, finally unite and terminate in the third sinus, 
which performs the office of a vein. In the spermatic 
vessels, commonly called vasa praeparantia, certain 
minute arteries proceeding from the great artery adhere 
to the venae praeparantes, which they accompany, and 
are at length taken in and included within their coats, 

Circulation of the Blood 129 

in such a way that they seem to have a common 
niding, so that where they terminate on the upper 
portion of the testis, on that cone-shaped process called 
the corpus varicosum et pampiniforme, it is altogether 
uncertain whether we are to regard their terminations 
as veins, or as arteries, or as both. In the same way- 
are the ultimate ramifications of the arteries which 
run to the umbilical vein, lost in the tunics of this 

What doubt can there be, if by such channels the 
great arteries, distended by the stream of blood sent 
into them, are relieved of so great and obvious a torrent, 
but that nature would not have denied distinct and 
visible passages, vortices, and estuaries, had she in- 
tended to divert the whole current of the blood, and 
had wished in this way to deprive the lesser branches 
and the solid parts of all the benefit of the influx of 
that fluid ? 

Finally, I shall quote this single experiment, which 
appears to me sufficient to clear up all doubts about 
the anastomoses, and their uses, if any exist, and to set 
at rest the question of a passage of the blood from 
the veins to the arteries, by any special channels, or by 

Having laid open the thorax of an animal, and tied 
the vena cava near the heart, so that nothing shall pass 
from that vessel into its cavities, and immediately after- 
wards, having divided the carotid arteries on both sides, 
the jugular veins being left untouched ; if the arteries 
be now perceived to become empty but not the veins, 
I think it will be manifest that the blood does nowhere 
pass from the veins into the arteries except through the 
ventricles of the heart. Were it not so, as observed by 
Galen, we should see the veins as well as the arteries 
emptied in a very short time, by the efflux from their 
corresponding arteries. 

For what further remains, oh Riolanus ! I congratu- 
late both myself and you : myself, for the opinion with 
l 262 

130 Circulation of the Blood 

which you have graced my Circulation ; and you, for 
your learned, polished, and terse production, than which 
nothing more elegant can be imagined. For the favour 
you have done me in sending me this work, I feel most 
grateful, and I would gladly, as in duty bound, proclaim 
my sense of its merits, but I confess myself unequal to 
the task ; for I know that the Enchiridion bearing the 
name of Riolanus inscribed upon it, has thereby more 
of honour conferred upon it than it can derive from 
any praise of mine, which nevertheless I would yield 
without reserve. The famous book will live for ever ; 
and when marble shall have mouldered, will proclaim 
to posterity the glory that belongs to your name. You 
have most happily conjoined anatomy with pathology, 
and have greatly enriched the subject with a new and 
most useful osteology. Proceed in your worthy career, 
most illustrious Riolanus, and love him who wishes 
that you may enjoy both happiness and length of days, 
and that all your admirable works may conduce to your 
eternal fame. 










It is now many years, most learned Riolanus, since, 
with the aid of the press, I published a portion of my 
work. But scarce a day, scarce an hour, has passed since 
the birth-day of the Circulation of the blood, that I have 
not heard something for good or for evil said of this my 
discovery. Some abuse it as a feeble infant, and yet 
unworthy to have seen the light ; others, again, think 
the bantling deserves to be cherished and cared for ; 
these oppose it with much ado, those patronize it with 
abundant commendation; one party holds that I have 
completely demonstrated the circulation of the blood by 
experiment, observation, and ocular inspection, against 
all force and array of argument ; another thinks it 
scarcely yet sufficiently illustrated — not yet cleared of 
all objections. There are some, too, who say that I 
have shown a vainglorious love of vivisections, and 
who scoff at and deride the introduction of frogs and 
serpents, flies, and others of the lower animals upon the 
scene, as a piece of puerile levity, not even refraining 
from opprobrious epithets. 

To return evil speaking with evil speaking, however, 
I hold to be unworthy in a philosopher and searcher 
after truth ; I believe that I shall do better and more 
advisedly if I meet so many indications of ill breeding 
with the light of faithful and conclusive observation. It 
cannot be helped that dogs bark and vomit their foul 
stomachs, or that cynics should be numbered among 
philosophers ; but care can be taken that they do not 


134 Circulation of the Blood 

bite or inoculate their mad humours, or with their dogs' 
teeth gnaw the bones and foundations of truth. 

Detractors, mummers, and writers defiled with abuse, 
as I resolved with myself never to read them, satisfied 
that nothing solid or excellent, nothing but foul terms, 
was to be expected from them, so have I held them 
still less worthy of an answer. Let them consume on 
their own ill nature ; they will scarcely find many well- 
disposed readers, I imagine, nor does God give that 
which is most excellent and chiefly to be desired — 
wisdom, to the wicked; let them go on railing, I say, 
until they are weary, if not ashamed. 

If for the sake of studying the meaner animals you 
should even enter the bakehouse with Heraclitus, as 
related in Aristotle, I bid you approach; for neither 
are the immortal Gods absent here, and the great and 
almighty Father is sometimes most visible in His lesser, 
and to the eye least considerable works. 1 

In my book on the Motion of the Heart and Blood 
in Animals, I have only adduced those facts from 
among many other observations, by which either errors 
were best refuted, or truth was most strongly supported ; 
I have left many proofs, won by dissection and appreci- 
able to sense, as redundant and unnecessary ; some of 
these, however, I now supply in brief terms, for the 
sake-v of the studious, and those who have expressed 
their desire to have them. 

The authority of Galen is of such weight with all, 
that I have seen several hesitate greatly with that experi- 
ment before, them, in which the artery is tied upon a 
tube placed within its cavity ; and by which it is pro- 
posed to prove that the arterial pulse is produced by a 
power communicated from the heart through the coats 
of the arteries, and not from the shock of the blood 
contained within them ; and thence, that the arteries 

1 To those who hesitated to visit him in his kiln or bakehouse (in-vw, 
which some have said should be imrui, rendered a dunghill) Heraclitus 
addressed the words in the text. Aristotle, who quotes them, has been 
defending the study of the lower animals. 

Circulation of the Blood 135 

dilate as bellows, are not filled as sacs. This experi- 
ment is spoken of by Vesalius, the celebrated anatomist ; 
but neither V esalius nor Galen sayj ^thnr he fori tried 
the experim ent^ which, how < . 1 did. Vesalius only 
prescribes, and Galen advises it. to those anxious to 
discover the truth, and for their better assurance, not 
thinking of the difficulties that attend its performance, 
nor of its futility when done; for indeed, although 
executed with the greatest skill, it supplies noth ing in 
support of the opinion which maintains that the coats 
of the vessel are the cause of the pulse ; it much rather 
proclaims that this, is owing to the impulse of the blood. 
For the moment you have thrown your ligature around 
the artery upon the reed or tube, immediately, by the 
force of the blood thrown in from above, it is dilated 
beyond the circle of the tube, by which the flow is 
impeded, and the shock is broken ; so that the artery 
which is tied only pulsates obscurely, being now cut off 
from the full force of the blood that flows through it, 
the shock being reverberated, as it were, from that part 
of the vessel which is above the ligature ; but if the 
artery below the ligature be now divided, the contrary 
of what has been maintained will be apparent, from the 
spurting of the blood impelled through the tube ; just 
as happens in the cases of aneurism, referred to in my 
book on the Motion of the Blood, which arise from an 
erosion of the coats of the vessel, and when the blood 
is contained in a membranous sac, formed not by the 
coats of the vessel dilated, but preternaturally produced 
from the surrounding tissues and flesh. The arteries 
beyond an aneurism of this kind will be felt beating 
very feebly, whilst in those above it and in the swelling 
itself the pulse will be perceived of great strength and 
fulness. And here we cannot imagine that the pulsa- 
tion and dilatation take place by the coats of the 
arteries, or any power communicated to the walls of the 
sac ; they are plainly due to the shock of the blood. 
But that the error of Vesalius, and the inexperience 

136 Circulation of the Blood 

of those who assert their belief that the part below the 
tube does not pulsate when the ligature is tied, may be 
made the more apparent, I can state, after having made 
the trial, that the inferior part will continue to pulsate 
if the experiment be properly performed; and whilst 
they say that when you have undone the ligature the 
inferior arteries begin again to pulsate, I maintain that 
the part below beats less forcibly when the ligature is 
untied than it did when the thread was still tight. But 
the effusion of blood from the wound confuses every- 
thing, and renders the whole experiment unsatisfactory 
and nugatory, so that nothing certain can be shown, 
by reason, as I have said, of the hemorrhage. But if, 
as I know by experience, you lay bare an artery, and 
control the divided portion by the pressure of your 
fingers, you may try many things at pleasure by which 
the truth will be made to appear. In the first place, 
you will feel the blood coming down in the artery at 
each pulsation, and visibly dilating the vessel. You 
may also at will suffer the blood to escape, by relaxing 
the pressure, and leaving a small outlet ; and you will 
see that it jets out with each stroke, with each con- 
traction of the heart, and with each dilatation of the 
artery, as I have said in speaking of arteriotomy, and 
the experiment of perforating the heart. And if you 
suffer the efflux to go on uninterruptedly, either from 
the simple divided artery or from a tube inserted into 
it, you will be able to perceive by the sight, and if you 
apply your hand, by the touch likewise, every character 
of the stroke of the heart in the jet ; the rhythm, order, 
intermission, force, &c, of its pulsations, all becoming 
sensible there, no otherwise than would the jets from a 
syringe, pushed in succession and with different degrees 
of force, received upon the palm of the hand, be obvious 
to sight and touch. I have occasionally observed the 
jet from a divided carotid artery to be so forcible, that, 
when received on the hand, the blood rebounded to 
the distance of four or five feet. 

Circulation of the Blood 137 

But that the question under discussion, viz. that the 
pulsific power does not proceed from the heart by the 
confs of the vessels, may he set in yet a dearer light, 
I beg here to refer to a portion of the descending 
aorta, about a span in length, with its division into the 
two crural trunks, which I removed from the body of 
a nobleman, and which is converted into a bony tube; 
by this hollow tube, nevertheless, did the arterial blood 
reach the lower extremities of this nobleman during his 
life, and cause the arteries in these to beat; and yet 
the main trunk was precisely in the same condition as 
is the artery in the experiment of Galen, when it is tied 
upon a hollow tube; where it was converted into bone- 
it could neither dilate nor contract like bellows, nor 
transmit the pulsific power from the heart to the 
inferi or ve ssels ; it could not convey a force which it 
was incapable of receiving through the solid matter of 
the bone. In spite of all, however, I well remember to 
have frequently noted the pulse in the legs and feet of 
this patient whilst he lived, for I was myself his most 
attentive physician, and he my very particular friend. 
The arteries in the inferior extremities of this nobleman 
must therefore and of necessity have been dilated by 
the impulse of the blood like flaccid sacs, and not have 
expanded in the manner of bellows through the action 
of their tunics. It is obvious, that whether an artery 
be tied over a hollow tube, or its tunics be converted 
into a bony and unyielding canal, the interruption to 
the pulsific power in the inferior part of the vessel must 
be the same. 

I have known another instance in which a portion of 
the aorta near the heart was found converted into bone, 
in the body of a nobleman, a man of great muscular 
strength. The experiment of Galen, therefore, or, at all 
events^ a state analogous to it, not effected on purpose 
but encountered by accident, makes it sufficiently 
to appear, that compression or ligature of the coats of 
an artery does not interfere with the pulsative proper- 

138 Circulation of the Blood 

ties of its derivative branches ; and indeed, if the 
experiment which Galen recommends were properly 
performed by any one, its results would be found in 
opposition to the views which Vesalius believed they 
would support. 

But we do not therefore deny everything like motion 
to the tunics of the arteries ; on the contrary, we allow 
them the same motions which we concede to the heart, 
viz. a diastole, and a systole or return from the distended 
to the natural state; this much we believe to be effected 
by a power inherent in the coats themselves. But it is 
to be observed, that they are not both dilated and con- 
tracted by the same, but by different causes and means ; 
as may be observed of the motions of all parts, and of 
the ventricle of the heart itself, which is distended by 
the auricle, contracted by its own inherent power ; 
so, the arteries are dilated by the stroke of the heart, 
but they contract or collapse of themselves. 1 

You may also perform another experiment at the 
same time : if you fill one of two basins of the same size 
with blood issuing per saltum from an artery, the other 
with venous blood from a vein of the same animal, you 
will have an opportunity of perceiving by the eye, both 
immediately and by and by, when the blood in either 
vessel has become cold, what differences there are 
between them. You will find that it is not as they 
believe who fancy that there is one kind of blood in 
the arteries .and another in the veins, that in the 
arteries being of a more florid colour, more frothy, 
and imbued with an abundance of I know not what 
spirits, effervescing and swelling, and occupying a 
greater space, like milk or honey set upon the fire. 
For were the blood which is thrown from the left 
ventricle of the heart into the arteries, fermented into 
any such frothy and flatulent fluid, so that a drop or 
two distended the whole cavity of the aorta ; unques- 

1 Vide Chapter III. of the Disquisition on the Motion of the Heart 
and Blood. 

Circulation of the Blood 139 

tionably, upon the subsidence of this fermentation, the 
blood would return to its original quantity of a few 
drops ; (and this, indeed, is the reason that some assign 
for the usually empty state of the arteries in the dead 
body ;) and so should it be with the arterial blood in 
the cup, for so it is with boiling milk and honey when 
they come to cool. But if in either basin you find 
blood nearly of the same colour, not of very different 
consistency in the coagulated state, forcing out serum 
in the same manner, and filling the cups to the same 
height when cold that it did when hot, this will be 
enough for any one to rest his faith upon, and afford 
argument enough, I think, for rejecting the dreams that 
have been promulgated on the subject. Sense and 
reason alike assure us that the blood contained in the 
left ventricle is not of a different nature from that in 
the right. And then, when we see that the mouth of 
the pulmonary artery is of the same size as the aorta, 
and in other respects equal to that vessel, it were 
imperative on us to affirm that the pulmonary artery 
was distended by a single drop of spumous blood, as 
well as the aorta, and so that the right as well as the 
left side of the heart was filled with a brisk or fermenting 

The particulars which especially dispose men's minds 
to admit diversity in the arterial and venous blood are 
three in number : one, because in arteriotomy the blood 
that flows is of a more florid hue than that which 
escapes from a vein ; a second, because in the dis- 
section of dead bodies the left ventricle of the heart, 
and the arteries in general, are mostly found empty; a 
third, because the arterial blood is believed to be more 
spirituous, and being replete with spirit is made to 
occupy a much larger space. The causes and reasons, 
however, wherefore all these things are so, present 
themselves to us when we ask after them. 

1 st. With reference to the colour it is to be observed, 
that wherever the blood issues by a very small orifice, 

140 Circulation of the Blood 

it is in some measure strained, and the thinner and 
lighter part, which usually swims on the top and is the 
most penetrating, is emitted. Thus, in phlebotomy, 
when the blood escapes forcibly and to a distance, in 
a full stream, and from a large orifice, it is thicker, has 
more body, and a darker body ; but, if it flows from a 
small orifice, and only drop by drop, as it usually does 
when the bleeding fillet is untied, it is of a brighter 
hue ; for then it is strained as it were, and the thinner 
and more penetrating portion only escapes ; in the same 
way, in the bleeding from the nose, in that which takes 
place from a leech-bite, or from scarifications, or in any 
other way by diapedesis or transudation, the bjood is 
always seen to have a brighter cast, because the thick- 
ness and firmness of the coats of the arteries render 
the outlet or outlets smaller, and less disposed to yield 
a ready passage to the outpouring blood ; it happens 
also that when fat persons arc let blood, the orifice of 
the vein is apt to be compressed by the subcutaneous 
fat, by which the blood is made to appear thinner, more 
florid, and in some sort arterious. On the other hand, 
the blood that flows into a basin from a large artery 
freely divided, will look venous. The blood in the 
lungs is of_a much more florid colour than it is in 
the arteries, and we know how it is strained through 
the pulmonary tissue. 

2d. The emptiness of the arteries in the dead body, 
which probably misled Erasistratus in supposing that 
they only contained aereal spirits, is caused by this, 
that when respiration ceases the lungs collapse, and 
then the passages through them are closed ; the heart, 
however, continues for a time to contract upon the 
blood, whence we find the left auricle more contracted, 
and the corresponding ventricle, as well as the arteries 
at large, appearing empty, simply because there is no 
supply of blood flowing round to fill them. In cases, 
however, in which the heart has ceased to pulsate and 
the lunys to afford a passage to the blood simul- 

Circulation of the Blood 141 

tancously, as in those who have died from drowning 
01 .syncope, or who die suddenly, you will find the 
arteries, as well as the veins, full of blood. 

3d. With reference- to the third point, or that of l ! e 
spirits, it may be said that, as it is still a question what 
they are, how extant in the body, of what consist! 
wh< ther separate and distinct from the blood and solids, 
or mingled with these, — upon each and all of these 
points there are so many and such conflicting opinions, 
that it is not wonderful that the spirits, whose nature- 
is thus left so wholly ambiguous, should serve as the 
common subterfuge of ignorance. Persons of limited 
information, when they are at a loss to assign a cause 
for anything, very commonly reply that it is done by 
the spirits ; and so they bring the spirits into play upon 
all occasions ; even as indifferent poets are always 
thrusting the gods upon the stage as a means of un- 
ravelling the plot, and bringing about the catastrophe. 

1'ernelius, and many others, suppose that there are 
aereal spirits and invisible substances. Fernelius proves 
that there are animal spirits, by saying that the cells 
in the brain are apparently unoccupied, and as nature 
abhors a vacuum, he concludes that in the living body 
they are filled with spirits, just as Erasistratus had held 
that, l>ecause the arteries were empty of blood, there- 
fore they must be filled with spirits. But Medical 
Sc hools admit th ^pp lrinrk nf .spirits. :_ the-jaatural 
spirits flowing through the veins, the vital spirits 
through the arteries, and the animal spirits through 
the nerves ; whence physicians say, out of Galen, that 
sometimes the parts of the brain are oppressed by 
sympathy, because the faculty with the essence, i.e. the 
spirit, is overwhelmed ; and sometimes this happens 
independently of the essence. Farther, besides the 
three orders of influxive spirits adverted to, a like 
number of implanted or stationary spirits seem to be 
acknowledged ; but we have found none of all these 
spirits by dissection, neither in the veins, nerves, 

142 Circulation of the Blood 

arteries, nor other parts of living animals. Some 
speak of corporeal, others of incorporeal spirits ; and 
they who advocate the corporeal spirits will have the 
blood, or the thinner portion of the blood, to be the 
bond of union with the soul, the spirit being contained 
in the blood as the flame is in the smoke of a lamp or 
candle, and held admixed by the incessant motion of 
the fluid ; others, again, distinguish between the spirits 
and the blood. They who advocate incorporeal spirits 
have no ground of experience to stand upon ; their 
spirits indeed are synonymous with powers or faculties, 
such as a concoctive spirit, a chylopoietic spirit, a pro- 
creative spirit, &c. — they admit as many spirits, in short, 
as there are faculties or organs. 

But then the schoolmen speak of a spirit of fortitude, 
prudence, patience, and the other virtues, and also of a 
most holy spirit of wisdom, and of every divine gift ; 
and they besides suppose that there are good and evil 
spirits that roam about or possess the body, that assist 
or cast obstacles in the way. They hold some diseases 
to be owing to a Cacoda?mon or evil spirit, as there 
are others that are due to a cacochemy or defective 

Although there is nothing more uncertain and 
questionable, then, than the doctrine of spirits that 
is proposed to us, nevertheless physicians seem for 
the major part to conclude, with Hippocrates, that 
our body is composed or made up of three elements, 
viz. containing parts, contained parts, and causes of 
action, spirits being understood by the latter term. 
But if spirits are to be taken as synonymous with 
causes of activity, whatever has power in the living 
body and a faculty of action must be included under 
the denomination. It would appear, therefore, that all 
spirits were neither aereal substances, nor powers, nor 
habits ; and that all were not incorporeal. 

But keeping in view the points that especially inter- 
est us, others, as leading to tediousness, being left 

Circulation of the Blood 143 

unnoticed, it seems that the spirits which flow by 
the veins or the arteries are not distinct from the 
blood, any more than the flame of a lamp is distinct 
from the inflammable vapour that is on fire; in short, 
that the blood and these spirits signify one and the 
same thing, though different, — like generous wine and 
its spirit ; for as wine, when it has lost all its spirit, is 
no longer wine, buta vapid liquor or vinegar; so blood 
without spirit is not blood, but something else — clot or 
cruor ; even as a hand of stone, or of a dead body, is 
no hand in the most complete sense, neither is blood 
void of the vital principle proper blood; it is imme- 
diately to be held as corrupt when deprived of its 
spirit. The spirit therefore which inheres in the 
arteries, and especially in the blood which fills them, 
is to be regarded either as its act or agent, in the same 
way as the spirit of wine in wine, and the spirit of aqua 
vitae in brandy, or as a flame kindled in alcohol, which 
lives and feeds on, or is nourished by itself. The 
blood consequently, though richly imbued with spirits, 
does not swell, nor ferment, nor rise to a head through 
them, so as to require and occupy a larger space, — a 
fact that may be ascertained beyond the possibility of 
question by the two cups of equal size ; it is to be 
regarded as wine, possessed of a large amount of spirits, 
or, in the Hippocratic sense, of signal powers of acting 
and effecting. 

It is therefore the same blood in the arteries that is 
found in the veins, although it may be admitted to be 
more spirituous, possessed of higher vital force in the 
former than in the latter ; but it is not changed into 
anything more vaporous, or more aereal, as if there 
were no spirits but such as are aereal, and no cause of 
action or activity that is not of the nature of flatus or 
wind. But neither the animal, natural, nor vital spirits 
which inhere in the solids, such as the ligaments and 
nerves (especially if they be of so many different 
species), and are contained within the viewless inter- 

144 Circulation of the Blood 

stices of the tissues, are to be regarded as so many 
different aereal forms, or kinds of vapour. 

And here I would gladly be informed by those who 
admit corporeal spirits, but of a gaseous or vaporous 
consistency, in the bodies of animals, whether or not 
they have the power of passing hither and thither, like 
distinct bodies independently of the blood ? Or whether 
the spirits follow the blood in its motions, either as 
integral parts of the fluid or as indissolubly connected 
with it, so that they can neither quit the tissues nor 
pass hither nor thither without the influx and reflux, 
and motion of the blood ? For if the spirits exhaling 
from the blood, like the vapour of water attenuated by 
heat, exist in a state of constant flow and succession as 
the pabulum of the tissues, it necessarily follows that 
they are not distinct from this pabulum, but are in- 
cessantly disappearing ; whereby it seems that they can 
neither have influx nor reflux, nor passage, nor yet 
remain at rest without the influx, the reflux, the passage 
[or stasis] of the blood, which is the fluid that serves as 
their vehicle or pabulum. 

And next I desire to know of those who tell us that 
the spirits are formed in the heart, being compounded 
of the vapours or exhalations of the blood (excited 
either by the heat of the heart or the concussion) and 
the inspired air, whether such spirits are not to be 
accounted much colder than the blood, seeing that 
both the elements of their composition, namely, air 
and vapour, are much colder? For the vapour of 
boiling water is much more bearable than the water 
itself; the flame of a candle is less burning than the 
red-hot snuff, and burning charcoal than incandescent 
iron or brass. Whence it would appear that spirits of 
this nature rather receive their heat from the blood, 
than that the blood is warmed by these spirits ; such 
spirits are rather to be regarded as fumes and excre 
mentitious effluvia proceeding from the body in the 
manner of odours, than in any way as natural artificers 

Circulation of the I>l<>od 145 

of the tissues ; 8 conclusion which we are the 1 
disposed to admit, when we see that they so spa 

lose any virtue they may possess, and which they had. 
derived from the blood as their source, — they aie at 
best of a very frail and evanescent nature. Wh 
also it becomes probable that the expiration of the 
js na means by which these vapours being cast 
off, the blood is fanned and purified ; whilst inspiration 
is a means by which the blood in its passage between 
the two ventricles of the heart is tempered by the cold 
of the ambient atmosphere, lest, getting heated, and 
blown up with a kind of fermentation, like milk or 
honey set over the fire, it should so distend the lungs 
that the animal got suffocated ; somewhat in the same 
way, perchance, as one labouring under a severe 
asthma, which Galen himself seems to refer to its 
proper cause when he says it is owing to an obstruction 
of the smaller arteries, viz. the vasa venosa et arteriosa. 
And I have found by experience that patients affected 
with asthma might be brought out of states of very 
imminent danger by having cupping-glasses applied, 
and a plentiful and sudden affusion of cold water [upon 
the chest]. Thus much — and perhaps it is more than 
was necessary — have I said on the subject of spirits in 
this place, for I felt it proper to define them, and to say 
something of their nature in a physiological disquisition. 
I shall only further add, that they who descant on the 
calidum innatum or innate heat, as an instrument of 
nature available for every purpose, and who speak of 
the necessity of heat as the cherisher and retainer in life 
of the several parts of the body, who at the same time 
admit that this heat cannot exist unless connected with 
something, and because they find no substance of any- 
thing like commensurate mobility, or which might keep 
pace with the rapid intlux and reflux of this heat (in 
affections of the mind especially), take refuge in spirits 
as most subtile substances, possessed of the most 
penetrating qualities, and highest mobility — these 

146 Circulation of the Blood 

persons see nothing less than the wonderful and almost 
divine character of the natural operations as pro- 
ceeding from the instrumentality of this common 
agent, viz. the calidum innatum ; they farther regard 
these spirits as of a sublime, lucid, ethereal, celestial, 
or divine nature, and the bond of the soul ; even as the 
vulgar and unlettered, when they do not comprehend 
the causes of various effects, refer them to the imme- 
diate interposition of the Deity. Whence they declare 
that the heat perpetually flowing into the several parts 
is in virtue of the influx of spirits through the channels 
of the arteries ; as if the blood could neither move so 
swiftly, nor penetrate so intimately, nor cherish so 
effectually. And such faith do they put in this 
opinion, such lengths are they carried by their belief, 
that they deny the contents of the arteries to be blood ! 
And then they proceed with trivial reasonings to 
maintain that the arterial blood is of a peculiar kind, 
or that the arteries are filled with such aereal spirits, 
and not with blood; all the while, in opposition to 
everything which Galen has advanced against Erasi- 
stratus, both on grounds of experiment and of reason. 
But that arterial blood differs in nothing essential from 
venous blood has been already sufficiently demonstrated; 
and our senses likewise assure us that the blood and 
spirits do not flow in the arteries separately and dis- 
joined, but as one body. 

We have occasion to observe so often as our hands, 
feet, or ears have become stiff and cold, that as they 
recover again by the warmth that flows into them, they 
acquire their natural colour and heat simultaneously ; 
that the veins which had become small and shrunk, 
swell visibly and enlarge, so that when they regain 
their heat suddenly they become painful ; from which 
it appears, that that which by its influx brings heat is 
the same which causes repletion and colour ; now this 
can be and is nothing but blood. 

When an artery and a vein are divided, any one may 

Circulation of the Blood 147 

clearly see that the part of the vein towards the heart 
pours out no blood, whilst that beyond the wound 
gives a torrent ; the divided artery, on the contrary, (as 
in my experiment on the carotids,) pours out a flood of 
pure blood from the orifice next the heart, and in jets 
as if it were forced from a syringe, whilst from the 
further orifice of the divided artery little or no blood 
escapes. This experiment therefore plainly proves in 
what direction the current sets in either order of vessels 
— towards the heart in the veins, from the heart in the 
arteries ; it also shows with what velocity the current 
moves, not gradually and by drops, but even with 
violence. And lest any one, by way of subterfuge, 
should take shelter in the notion of invisible spirits, 
let the orifice of the divided vessel be plunged under 
water or oil, when, if there be any air contained in it, 
the fact will be proclaimed by a succession of visible 
bubbles. Hornets, wasps, and other insects of the 
same description plunged in oil, and so suffocated, 
emit bubbles of air from their tail whilst they are 
dying ; whence it is not improbable that they thus 
respire when alive ; for all animals submerged and 
drowned, when they finally sink to the bottom and 
die, emit bubbles of air from the mouth and lungs. 
It is also demonstrated by the same experiment, that 
the valves of the veins act with such accuracy, that air 
blown into them does not penetrate ; much less then 
can blood make its way through them : — it is certain, 
I say, that neither sensibly nor insensibly, nor gradually 
and drop by drop, can any blood pass from the heart 
by the veins. 

And that no one may seek shelter in asserting that 
these things are so when nature is disturbed and 
opposed, but not when she is left to herself and at 
liberty to act ; that the same things do not come to 
pass in morbid and unusual states as in the healthy 
and natural condition ; they are to be met by saying, 
that if it were so, if it happened that so much blood 

148 Circulation of the Blood 

was lost from the farther orifice of a divided vein 
because nature was disturbed, still that the incision 
does not close the nearer orifice, from which nothing 
either escapes or can be expressed, whether nature be 
disturbed or not. Others argue in the same way, main- 
taining that, although the blood immediately spurts out 
in such profusion with every beat, when an artery is 
divided near the heart, it does not therefore follow that 
the blood is propelled by the pulse when the heart and 
artery are entire. It is most probable, however, that 
every stroke impels something ; and that there would 
be no pulse of the container, without an impulse being 
communicated to the thing contained, seems certain. 
Yet some, that they may seize upon a farther means 
of defence, and escape the necessity of admitting the 
circulation, do not fear to affirm that the arteries in the 
living body and in the natural state are already so full 
of blood, that they are incapable of receiving another 
drop ; and so also of the ventricles of the heart. But 
it is indubitable that, whatever the degree of distension 
and the extent of contraction of the heart and arteries, 
they are still in a condition to receive an aditional 
quantity of blood forced into them, and that this is 
far more than is usually reckoned in grains or drops, 
seems also certain. For if the ventricles become so 
excessively distended that they will admit no more 
blood, the heart ceases to beat, (and we have occasional 
opportunities of observing the fact in our vivisections,) 
and, continuing tense and resisting, death by asphyxia 

In the work on the Motion of the Heart and Blood, 
I have already sufficiently discussed the question as to 
whether the blood in its motion was attracted, or im- 
pelled, or moved by its own inherent nature. I have 
there also spoken at length of the action and office, of 
the dilatation and contraction of the heart, and have 
shown what these truly are, and how the heart contracts 
during the diastole of the arteries ; so that I must hold 

Circulation of the Blood 149 

those who take points for dispute from among them as 
either not understanding the subject, or as unwilling to 
look at things for themselves, and to investigate them 
with their own sen- i. 1 

For my part, I believe that no other kind of attraction 
can be demonstrated in the living body save that of the 
nutriment, which gradually and incessantly passes on to 
supply the waste that takes place in the tissues ; in the 
same way as the oil rises in the wick of a lamp to be 
consumed by the flame. Whence I conclude that the 
primary and common organ of all sensible attraction 
and impulsion is of the nature of sinew (nervus), or 
fibre, or muscle, and this to the end that it may be 
contractile, that contracting it may be shortened, and 
so either stretch out, draw towards, or propel. But 
these topics will be better discussed elsewhere, when 
we speak of the organs of motion in the animal 

To those who repudiate the circulation because they 
neither see the efficient nor final cause of it, and who 
exclaim, cui bono ? I have yet to reply, having hitherto 
taken no note of the ground of objection which they 
take up. And first I own I am of opinion that our first 
duty is to inquire whether the thing be or not, before 
asking wherefore it is? for from the facts and circum- 
stances which meet us in the circulation admitted, 
established, the ends and objects of its institution are 
especially to be sought. Meantime I would only ask, 
how many things we admit in physiology, pathology, 
and therapeutics, the causes of which are unknown to 
us ? That there are many, no one doubts — the causes 
of putrid fevers, of revulsions, of the purgation of 
excrementitious matters, among the number. 

Whoever, therefore, sets himself in opposition to the 
circulation, because, if it be acknowledged, he cannot 
account for a variety of medical problems, nor in 
the treatment of diseases and the administration of 

' Vide Chapter XIV. 

150 Circulation of the Blood 

medicines, give satisfactory reasons for the phenomena 
that appear ; or who will not see that the precepts he 
has received from his teachers are false ; or who thinks 
it unseemly to give up accredited opinions ; or who 
regards it as in some sort criminal to call in question 
doctrines that have descended through a long succes- 
sion of ages, and carry the authority of the ancients ; — 
to all of these I reply : that the facts cognizable by the 
senses wait upon no opinions, and that the works of 
nature bow to no antiquity ; for indeed there is nothing 
either more ancient or of higher authority than nature. 
To those who object to the circulation as throwing 
obstacles in the way of their explanations of the 
phenomena that occur in medical cases (and there 
are persons who will not be content to take up with 
a new system, unless it explains everything, as in 
astronomy), and who oppose it with their own errone- 
ous assumptions, such as that, if it be true, phlebotomy 
cannot cause revulsion, seeing that the blood will still 
continue to be forced into the affected part ; that the 
passage of excrementitious matters and foul humours 
through the heart, that most noble and principal viscus, 
is to be apprehended ; that an efflux and excretion, 
occasionally of foul and corrupt blood, takes place 
from the same body, from different parts, even from 
the same part and at the same time, which, were the 
blood agitated by a continuous current, would be shaken 
and effectually mixed in passing through the heart, and 
many points of the like kind admitted in our medical 
schools, which are seen to be repugnant to the doctrine 
of the circulation, — to them I shall not answer farther 
here, than that the circulation is not always the same in 
every place, and at every time, but is contingent upon 
many circumstances : the more rapid or slower motion 
of the blood, the strength or weakness of the heart as 
the propelling organ, the quantity and quality or con- 
stitution of the blood, the rigidity or laxity of the 
tissues and the like. A thicker blood, of course, 

Circulation of the Blood 151 

moves more slowly through narrower channels; it is 
more effectually strained in its passage through the 
substance of the liver than through that of the lui 
It has not the same velocity through flesh and the 
softer parenchymatous structures and through sinewy 
parts of greater compactness and consistency : for the 
thinner and purer and more spirituous part permeates 
more quickly, the thicker more earthy and indifferently 
concocted portion moves more slowly, or is refused 
admission. The nutritive portion, or ultimate aliment 
of the tissues, the dew or cambium, is of a more pene- 
trating nature, inasmuch as it has to be added every- 
where, and to everything that grows and is nourished 
in its length and thickness, even to the horns, nails, 
hair, and feathers ; and then the excrementitious 
matters have to be secreted in some places, where 
they accumulate, and either prove a burthen or are 
concocted. But I do not imagine that the excremen- 
titious fluids or bad humours when once separated, nor 
the milk, the phlegm, and the spermatic fluid, nor the 
ultimate nutritive part, the dew or cambium, necessarily 
circulate with the blood : that which nourishes every 
part adheres and becomes agglutinated to it. Upon 
each of these topics and various others besides, to be 
discussed and demonstrated in their several places, viz. 
in the physiology and other parts of the art of medicine, 
as well as of the consequences, advantages or dis- 
advantages of the circulation of the blood, I do not 
mean to touch here ; it were fruitless indeed to do so 
until the circulation has been established and conceded 
as a fact. And here the example of ast-ronomy is by 
no means to be followed, in which from mere appear- 
ances or phenomena that which is in fact, and the 
reason wherefore it is so, are investigated. But as 
he who inquires into the cause of an eclipse must 
be placed beyond the moon if he would ascertain it 
by sense, and not by reason, still in reference to things 
sensible, things that come under the cognizance of the 

152 Circulation of the Blood 

senses, no more certain demonstration or means of 
gaining faith can be adduced than examination by the 
senses, than ocular inspection. 

There is one remarkable experiment which I would 
have every one try who is anxious for truth, and by 
which it is clearly shown that the_arterial pulse is owing 
to the impulse of the bloocLj Let apportion of the 
dried intestine of a dag l5f~woTf, or any other animal, 
such as we see hung up in the druggists' shops, be 
' taken and filled with water, and then secured at both 
ends like a sausage : by tapping with the finger at one 
extremity, you will immediately feel a pulse and vibration 
in any other part to which you apply the fingers, as you 
do when you feel the pulse at the wrist. In this way, 
indeed, and also by means of a distended vein, you 
may accurately, either in the dead or living body, 
imitate and show every variety of the pulse, whether as 
to force, frequency, volume, rhythm, &c. Just as in a 
long bladder full of fluid, or in an oblong drum, every 
stroke upon one end is immediately felt at the other ; 
so also in a dropsy of the belly and in abscesses under 
the skin, we are accustomed to distinguish between 
collections of fluid and of air, between anasarca and 
tympanites in particular. If a slap or push given on 
one side is clearly felt by a hand placed on the other 
side, we judge the case to be tympanites [?] ; not, as 
falsely asserted, because we hear a sound like that of 
a drum, and this produced by flatus, which never 
happens [?] ; but because, as in a drum, every the 
slightest tap passes through and produces a certain 
vibration on the opposite side ; for it indicates that 
there is a serous and ichorous substance present, of 
such a consistency as urine, and not any sluggish or 
viscid matter as in anasarca, which when struck retains 
the impress of the blow or pressure, and does not 
transmit the impulse. 

Having brought forward this experiment I may 
observe, that a most formidable objection to the cir- 

Circulation of the Blood 153 

culation of the blood rises out of it, which, however, 
has neither been observed nor adduced by any one \ 

has written against me. When we see by the experiment 
JUSt described, the systole and diastole of the pulse 
can be accurately imitated without any escape of fluid, 
it is obvious that the sa me ^ th ing may take place in the 
arter ies from the stroke*of the he art, without the necessity 
for a circulatiim T'Dut like E uriuus. with a me.rf; motion 
of the blood alternately backwards and forwards. Hut 
we have already satisfactorily replied to this difficulty ; 
and now we venture to say that the thing could not be 
so in the arteries of a living animal ; to be assured of 
this it is enough - to see thaffthe right auricle is inces- 
santly injecting the right ventricle of the heart with 
blood, The return of which is effectually prevented by 
the tricuspid valves ; the left auricle in like manner 
filling thejeft ventricle, the return of the blood there 
being opposed "by the mitral valves : and then the 
ventricles in their turn are propelling the blood into 
either great artery, the reflux in each being prevented 
by the sigmoid valves in its orifice. Either, conse- 
quently, the blood must move on incessantly through 
the lungs, and in like manner within the arteries of the 
body, or stagnating and pent up, it must rupture the 
containing vessels, or choke the heart by over disten- 
sion, as I have shown it to do in the vivisection of a 
snake, described in my book on the Motion of the 
Blood. To resolve this doubt I shall relate two 
experiments among many others, the first of which, 
indeed, I have already adduced, and which show with 
singular clearness that the blood flows incessantly and 
with great force and in ample abundance in the veins 
towards the heart. The internal jugular vein of a live 
fallow deer having been exposed, (many of the nobility 
and his most serene majesty the king, my master, being 
present,) was divided ; but a few drops of blood were 
observed to escape from the lower orifice rising up 
from under the clavicle; whilst from the superior orifice 

154 Circulation of the Blood 

of the vein and coming down from the head, a round 
torrent of blood gushed forth. You may observe the 
same fact any day in practising phlebotomy : if with 
a finger you compress the vein a little below the orifice, 
the flow of blood is immediately arrested ; but the 
pressure being removed, forthwith the flow returns 
as before. 

From any long vein of the forearm get rid of the 
blood as much as possible by holding the hand aloft 
and pressing the blood towards the trunk, you will 
perceive the vein collapsed and leaving, as it were, in 
a furrow of the skin ; but now compress the vein with 
the point of a finger, and you will immediately perceive 
all that part of it which is towards the hand, to enlarge 
and to become distended with the blood that is coming 
from the hand. How comes it when the breath is held 
and the lungs thereby compressed, a large quantity of 
air having been taken in, that the vessels of the chest 
are at the same time obstructed, the blood driven into 
the face, and the eyes rendered red and suffused ? 
Why is it, as Aristotle asks in his problems, that all 
the actions are more energetically performed when the 
breath is held than when it is given ? In like manner, 
when the frontal and lingual veins are incised, the blood 
is made to flow more freely by compressing the neck 
and holding the breath. I have several times opened 
the breast and pericardium of a man within two hours 
after his execution by hanging, and before the colour 
had totally left the face, and in presence of many 
witnesses, have demonstrated the right auricle of the 
heart and lungs distended with blood ; the auricle 
in particular of the size of a large man's fist, and so full 
of blood that it looked as if it would burst. This great 
distension, however, had disappeared next day, the 
body having stiffened and become cold, and the blood 
having made its escape through various channels. 
These and other similar facts, therefore, make it 
sufficiently certain that the blood flows through the 

Circulation of the Blood 155 

whole of the veins of the body towards the base of the 
heart, and that unless there was a further pa! 
afforded it, it would be pent up in these channels, 
ur would oppress and overwhelm the heart ; as on the 

other hand, did it not flow outwards by the arteries, but 
was found regurgitating, it would soon be seen how 
much it would oppress. 

I add another observation. A noble knight, Sir 
Robert Darcy, an ancestor of that celebrated physician 
and most learned man, my very dear friend Dr. Argent, 
when he had reached to about the middle period - >f 
life, made frequent complaint of a certain distressing 
pain in the chest, especially in the night season ; so that 
dreading at one time syncope, at another suffocation in 
his attacks he led an unquiet and anxious life. He 
tried many remedies in vain, having had the advice 
of almost every medical man. The disease going on 
from bad to worse, he by and by became cachectic and 
dropsical, and finally, grievously distressed, he died in 
one of his paroxysms. In the body of this gentleman, 
at the inspection of which there were present Dr. Argent, 
then president of the College of Physicians, and Dr. 
Gorge, a distinguished theologian and preacher, who 
was pastor of the parish, we found the wall of the left 
ventricle of the heart ruptured, having a rent in it of 
size sufficient to admit any of my fingers, although the 
wall itself appeared sufficiently thick and strong ; this 
laceration had apparently been caused by an impediment 
to the passage of the blood from the left ventricle into 
the arteries. 

I was acquainted with another strong man, who 
having received an injury and affront from one more 
powerful than himself, and upon whom he could not 
have his revenge, was so overcome with hatred and 
spite and passion, which he yet communicated to no 
one, that at last he fell into a strange distemper, suffer- 
ing from extreme oppression and pain of the heart and 
breast, and the prescriptions of none of the very best 

156 Circulation of the Blood 

physicians proving of any avail, he fell in the course of 
a few years into a scorbutic and cachectic state, became 
tabid and died. This patient only received some little 
relief when the whole of his chest was pummelled or 
kneaded by a strong man, as a baker kneads dough. 
His friends thought him poisoned by some maleficent 
influence, or possessed with an evil spirit. His jugular 
arteries, enlarged to the size of the thumb, looked like 
the aorta itself, or they were as large as the descending 
aorta ; they had pulsated violently, and appeared like 
two long aneurisms. These symptoms had led to trying 
the effects of arteriotomy in the temples, but with no 
relief. In the dead body I found the heart and aorta 
so much gorged and distended with blood, that the 
cavities of the ventricles equalled those of a bullock's 
heart in size. Such is the force of the blood pent up, 
and such are the effects of its impulse. 

We may therefore conclude, that although there may 
be impulse without any exit, as illustrated in the experi- 
ment lately spoken of, still that this could not take 
place in the vessels of living creatures without most 
serious dangers and impediments. From this, however, 
it is manifest that the blood in its course does not 
everywhere pass with the same celerity, neither with the 
same force in all places and at all times, but that it 
varies greatly according to age, sex, temperament, habit 
of body, and other contingent circumstances, external 
as well as internal, natural or non-natural. For it does 
not course through intricate and obstructed passages 
with the same readiness that it does through straight, 
unimpeded, and pervious channels. Neither does it 
run through close, hard, and crowded parts, with the 
same velocity as through spongy, soft, and permeable 
tissues. Neither does it flow and penetrate with such 
swiftness when the impulse [of the heart] is slow and 
weak, as when this is forcible and frequent, in which 
case the blood is driven onwards with vigour and in 
large quantity. Nor is the same blood, when it has 

Circulation of the Blood 157 

become moi consistent or earthy, so penetrative as 
when it is more serous and attenuated or liquid. And 
then it seems only reasonable to think that the bl 
in its circuit passes more slowly through the kidneys 
than through the substance of the heart ; more swiftly 
through the liver than through the kidneys; through 
the spleen more quickly than through the lungs, and 
through the lungs more speedily than through any of 
the other viscera or the muscles, in proportion always 
to the denseness or spi mginess of the tissue of each. 

We may be permitted to take the same view of the 
influence of age, sex, temperament, and habit of body, 
whether this be hard or soft ; of that of the ambient 
cold which condenses bodies, and makes the veins 
in the extremities to shrink and almost to disappear, 
and deprives the surface both of colour aud heat ; 
and also that of meat and drink which render the 
blood more watery, by supplying fresh nutritive matter. 
From the veins, therefore, the blood flows more freely 
in phlebotomy when the body is warm than when it is 
cold. We also observe the signal influence of the 
affections of the mind when a timid person is bled and 
happens to faint : immediately the flow of blood is 
arrested, a deadly pallor overspreads the surface, the 
limbs stiffen, the ears sing, the eyes are dazzled or 
blinded, and, as it were, convulsed. But here I come 
upon a field where I might roam freely and give myself 
up to speculation. And, indeed, such a flood of light 
and truth breaks in upon me here; occasion offers of 
explaining so many problems, of resolving so many 
doubts, of discovering the causes of so many slighter 
and more serious diseases, and of suggesting remedies 
for their cure, that the subject seems almost to demand 
a separate treatise. And it will be my business in my 
" Medical Observations," to lay before my reader matter 
upon all these topics which shall be worthy of the 
gravest consideration. 

And what indeed is more deserving of attention than 

158 Circulation of the Blood 

the fact that in almost every affection, appetite, hope, 
or fear, our body suffers, the countenance changes, and 
the blood appears to course hither and thither. In 
anger the eyes are fiery and the pupils contracted ; 
in modesty the cheeks are suffused with blushes ; in 
fear, and under a sense of infamy and of shame, the 
face is pale, but the ears burn as if for the evil they 
heard or were to hear ; in lust how quickly is the 
member distended with blood and erected ! But, above 
all, and this is of the highest interest to the medical 
practitioner, — how speedily is pain relieved or removed 
by the detraction of blood, the application of cupping- 
glasses, or the compression of the artery which leads 
to a part? It sometimes vanishes as if by magic. 
But these are topics that I must refer to my " Medical 
Observations," where they will be found exposed at 
length and explained. 

Some weak and inexperienced persons vainly seek 
by dialectics and far-fetched arguments, either to upset 
or establish things that are only to be founded on 
anatomical demonstration, and believed on the evidence 
of the senses. He who truly desires to be informed 
of the question in hand, and whether the facts alleged 
be sensible, visible, or not, must be held bound either 
to look for himself, or to take on trust the conclusions 
to which they have come who have looked ; and indeed 
there is no higher method of attaining to assurance 
and certainty. Who would pretend to persuade those 
who had never tasted wine that it was a drink much 
pleasanter to the palate than water ? By what reason- 
ing should we give the blind from birth to know that 
the sun was luminous, and far surpassed the stars in 
brightness ? And so it is with the circulation of the 
blood, which the world has now had before it for so 
many years, illustrated by proofs cognizable by the 
senses, and confirmed by various experiments. No 
one has yet been found to dispute the sensible facts, 
the motion, efflux and afflux of the blood, by like 

Circulation of the Blood 159 

observations based on the evidence of sense, or to 
oppose the experiments adduced, by other experiments 
of the same character ; nay, no one has yet attempted 
an opposition on the ground of ocular testimony. 

There have not been wanting many who, inex- 
perienced and ignorant of anatomy, and making no 
appeal to the senses in their opposition, have, on the 
contrary, met it with empty assertions, and mere 
suppositions, with assertions derived from the lessons 
of teachers and captious cavillings; many, too, have 
vainly sought refuge in words, and these not always 
very nicely chosen, but reproachful and contumelious; 
which, however, have no farther effect than to expose 
their utterer's vanity and weakness, and ill breeding 
and lack of the arguments that are to be sought in 
the conclusions of the senses, and false sophistical 
reasonings that seem utterly opposed to sense. Even 
as the waves of the Sicilian sea, excited by the blast, 
dash against the rocks around Charybdis, and then 
hiss and foam, and are tossed hither and thither ; so 
do they who reason against the evidence of their 

Were nothing to be acknowledged by the senses 
without evidence derived from reason, or occasionally 
even contrary to the previously received conclusions of 
reason, there would now be no problem left for dis- 
cussion. Had we not our most perfect assurances by 
the senses, and were not their perceptions confirmed 
by reasoning, in the same way as geometricians proceed 
with their figures, we should admit no science of any 
kind ; for it is the business of geometry, from things 
sensible, to make rational demonstration of things that 
are not sensible ; to render credible or certain things 
abstruse and beyond sense from things more manifest 
and better known. Aristotle counsels us better when, 
in treating of the generation of bees, he says : l " Faith 
is to be given to reason, if the matters demonstrated 

1 De Generat. Animal, lib. iii, cap. r. 

160 Circulation of the Blood 

agree with those that are perceived by the senses ; 
when the things have been thoroughly scrutinized, then 
are the senses to be trusted rather than the reason." 
Whence it is our duty to approve or disapprove, to 
receive or reject everything only after the most careful 
examination ; but to examine, to test whether anything 
have been well or ill advanced, to ascertain whether 
some falsehood does not lurk under a proposition, it 
is imperative on us to bring it to the proof of sense, 
and to admit or reject it on the decision of sense. 
Whence Plato in his Critias says, that the explanation 
of those things is not difficult of which we can have 
experience ; whilst they are not of apt scientific appre- 
hension who have no experience. 

How difficult is it to teach those who have no 
experience, the things of which they have not any 
knowledge by their senses ! And how useless and 
intractable, and unimpregnable to true science are such 
auditors ! They show the judgment of the blind in 
regard to colours, of the deaf in reference to concords. 
Who ever pretended to teach the ebb and flow of the 
tide, or from a diagram to demonstrate the measure- 
ments of the angles and the proportions of the sides 
of a triangle to a blind man, or to one who had 
never seen the sea nor a diagram ? He who is not 
conversant with anatomy, inasmuch as he forms no 
conception of the subject from the evidence_p'f hTs 
own eyes, is virtually blind to all thai.. -concerns 
anatomy, and unfit to appreciate what is founded 
thereon ; he knows nothing of that whi ch occ upies 
the attention of the anatomist, nor"ofThe principles 
inherent in the nature of the things which guide him 
in his reasonings ; facts and inferences as well as their 
sources are alike unknown to such a one. But no 
kind of science can possibly flow, save from some 
pre-existing knowledge of more obvious things ; and 
this is one main reason why our science in regard to 
the nature of celestial bodies, is so uncertain and 

Circulation of the Blood 161 

conjectural. I would ask of those who profess a 
knowledge of the causes of all things, why the two 
eyes keep constantly moving together, up or down, 
to this side or to that, and not independently, one 
looking this way, another that ; why the two auricles 
of the heart contract simultaneously, and the like? 
Are fevers, pestilence, and the wonderful properties of 
various medicines to be denied because their causes 
are unknown? Who can tell us why the fcetus in 
utero, breathing no air up to the tenth month of its 
existence, is yet not suffocated? Born in the course 
of the seventh or eighth month, and having once 
breathed, it is nevertheless speedily suffocated if its 
ration be interrupted. Why can the fcetus still 
contained within the uterus, or enveloped in the 
membranes, live without respiration; whilst once 
exposed to the air, unless it breathes it inevitably 
dies? 2 

Observing that many hesitate to acknowledge the 
circulation, and others oppose it, because, as I con- 
ceive, they have not rightly understood me, I shall 
here recapitulate briefly what I have said in my work 
on the Motion of the Heart and Blood, The blood 
contained in the veins, in its magazine, and where it 
is collected in largest quantity, viz. in the vena cava, 
close to the base of the heart and right auricle, gradually 
increasing in temperature by its internal heat, and be- 
coming attenuated, swells and rises like bodies in a 
state of fermentation, whereby the auricle being dilated, 
and then contracting, in virtue of its pulsative power, 
forthwith delivers its charge into the right ventricle ; 
which being filled, and the systole ensuing, the charge, 
hindered from returning into the auricle by the tricuspid 
valves, is forced into the pulmonary artery, which stands 
open to receive it, and is immediately distended with 
it. Once in the pulmonary artery, the blood cannot 
return, by reason of the sigmoid valves ; and then the 

1 Vide Chapter VI. of the Duq. on the Motion of the Heart and Bluod. 

1 62 Circulation of the Blood 

lungs, alternately expanded and contracted during in- 
spiration and expiration, afford it passage by the proper 
vessels into the pulmonary veins ; from the pulmonary 
veins, the left auricle, acting equally and synchronously 
with the right auricle, delivers the blood into the left 
ventricle ; which acting harmoniously with the right 
ventricle, and all regress being prevented by the mitral 
valves, the blood is projected into the aorta, and con- 
sequently impelled into all the arteries of the body. 
The arteries, filled by this sudden push, as they cannot 
discharge themselves so speedily, are distended ; they 
receive a shock, or undergo their diastole. But as 
this process goes on incessantly, I infer that the arteries 
both of the lungs and of the body at large, under the 
influence of such a multitude of strokes of the heart 
and injections of blood, would finally become so over- 
gorged and distended, that either any further injection 
must cease, or the vessels would burst, or the whole 
blood in the body would accumulate within them, were 
there not an exit provided for it. 

The same reasoning is applicable to the ventricles of 
the heart : distended by the ceaseless action of the 
auricles, did they not disburthen themselves by the 
channels of the arteries, they would by and by become 
over-gorged, and be fixed and made incapable of all 
motion. Now this, my conclusion, is true and neces- 
sary, if my premises be true ; but that these are either 
true or false, our senses must inform us, not our reason 
— ocular inspection, not any process of the mind. 

I maintain further, that the blood in the veins always 
and everywhere flows from less to greater branches, and 
from every part towards the heart; whence I gather 
that the whole charge which the arteries receive, and 
which is incessantly thrown into them, is delivered to 
the veins, and flows back by them to the source whence 
it came. In this way, indeed, is the circulation of the 
blood established : by an efflux and reflux from and to 
the heart ; the fluid being forcibly projected into the 


■ i 

v yv 

Circulation of the Blood 163 

arterial system, and then absorbed and imbibed from 
every part by the veins, it returns through these in a 
continuous stream. That all this is so, sense assures 
us ; and necessary inference from the perceptions of 
sense takes away all occasion for doubt. Lastly, this is 
what I have striven, by my observations and experi- 
ments, To illustrate and make known; I have not 
endeavoured from causes and probable principles to 
demonstrate my propositions, but, as of higher authority, 
to estHTflTsrx them by appeals to sense and experiment, 
after the manner of anatomists. 

And here I would refer to the amount of force, even 
of violence, which sight and touch make us aware of in 
the heart and greater arteries ; and to the systole and 
diastole constituting the pulse in the large warm-blooded 
animals, which I do not say is equal in all the vessels 
containing blood, nor in all animals that have blood ; 
but which is of such a nature and amount in all, that a 
flow and rapid passage of the blood through the smaller 
arteries, the interstices of the tissues, and the branches 
of the veins, must of necessity take place ; and therefore 
there is a circulation. 

For neither do the most minute arteries, nor the 
veins, pulsate ; but the larger arteries and those near 
the heart pulsate, because they do not transmit the 
blood so quickly as they receive it. 1 Having exposed 
an artery, and divided it so that the blood shall flow out 
as fast and freely as it is received, you will scarcely 
perceive any pulse in that vessel ; and for the simple 
reason, that an open passage being afforded, the blood 
escapes, merely passing through the vessel, not dis- 
tending it. In fishes, serpents, and the colder animals, 
the heart beats so slowly and feebly, that a pulse can 
scarcely be perceived in the arteries ; the blood in them 
is transmitted gradually. Whence in them, as also in 
the smaller branches of the arteries in man, there is no 
distinction between the coats of the arteries and veins, 

1 Vide Chapter III, on the Motion of the Heart and Blood. 

164 Circulation of the Blood 

because the arteries have to sustain no shock from the 
impulse of the blood. 

An artery denuded and divided in the way I have 
indicated, sustains no shock, and therefore does not 
pulsate ; whence it clearly appears that the arteries have 
no inherent pulsative power, and that neither do they 
derive any from the heart; but that they undergo their 
diastole solely from the impulse of the blood; for in 
the full stream, flowing to a distance, you may see the 
systole and diastole, all the motions of the heart — their 
order, force, rhythm, &c., x as it were in a mirror, and 
even perceive them by the touch. Precisely as in the 
water that is forced aloft, through a leaden pipe, by 
working the piston of a forcing-pump, each stroke of 
which, though the jet be many feet distant, is neverthe- 
less distinctly perceptible, — the beginning, increasing 
strength, and end of the impulse, as well as its amount, 
and the regularity or irregularity with which it is given, 
being indicated, the same precisely is the case from the 
orifice of a divided artery; whence, as in the instance 
of the forcing engine quoted, you will perceive that the 
efflux is uninterrupted, although the jet is alternately 
greater and less. In the arteries, therefore, besides the 
concussion or impulse of the blood, the pulse or beat 
of the artery, which is not equally exhibited in all, 
there is a perpetual flow and motion of the blood, 
which returns in an unbroken stream to the point 
from whence it commenced — the right auricle of the 

All these points you may satisfy yourself upon, by 
exposing one of the longer arteries, and having taken it 
between your finger and thumb, dividing it on the side 
remote from the heart. By the greater or less pressure 
of your fingers, you can have the vessel pulsating less 
or more, or losing the pulse entirely, and recovering it 
at will. And as these things proceed thus when the 
chest is uninjured, so also do they go on for a short 

1 Vide Chapter III, on the Motion of the Heart and Blood. 

Circulation of the Blood 165 

time when the thorax is laid open, and the lungs having 
collapsed, all the respiratory motions have ceased; 
here, nevertheless, for a little while you may perceive 
the left auricle contracting and emptying itself, and 
becoming whiter; but by and by growing weaker and 
weaker, it begins to intermit, as does the left ventricle 
also, and then it ceases to beat altogether, and becomes 
quiescent. Along with this, and in the same measure, 
does the stream of blood from the divided artery grow 
less and less, the pulse of the vessel weaker and weaker, 
until at last, the supply of blood and the impulse of the 
left ventricle failing, nothing escapes from it. You may 
perform the same experiment, tying the pulmonary 
veins, and so taking away the pulse of the left auricle, 
or relaxing the ligature, and restoring it at pleasure. 
In this experiment, too, you will observe what happens 
in moribund animals — viz. that the left ventricle first 
ceases from pulsation and motion, then the left auricle, 
next the right ventricle, finally the right auricle; so 
that where the vital force and pulse first begin, there 
do they also last fail. 

All of these particulars having been recognized by the 
senses, it is manifest that the blood passes through 
the lungs, not through the septum [in its course from 
the right to the left side of the heart], and only through 
them when they are moved in the act of respiration, 
not when they are collapsed and quiescent; whence we 
see the probable reasonHvtrerefore nature has instituted 
the foramen ovale in the foetus, instead of sending the 
blood by the way of the pulmonary artery into the left 
auricle and ventricle, which foramen she closes when 
the new-born creature begins to breathe freely. We 
can also now understand why, when the vessels of the 
lungs become congested and oppressed, and in those 
who are affected with serious diseases, it should be so 
dangerous and fatal a symptom when the respiratory- 
organs become implicated. 

We perceive further, why the blood is so florid in 

1 66 Circulation of the Blood 

the lungs, which is, because it is thinner, as having 
there to undergo filtration. 

Still further ; from the summary which precedes, and 
by way of satisfying those who are importunate in 
regard to the causes of the circulation, and incline to 
regard the power of the heart as competent to every- 
thing — as that it is not only the seat and source of the 
pulse which propels the blood, but also, as Aristotle 
thinks, of the power which attracts and produces it ; 
moreover, that the spirits are engendered by the heart, 
and the influxive vital heat, in virtue of the innate heat 
of the heart, as the immediate instrument of the soul, 
or common bond and prime organ in the performance 
of every act of vitality ; in a word, that the motion, 
perfection, heat, and every property besides of the 
blood and spirits are derived from the heart, as their 
fountain or original, (a doctrine as old as Aristotle, who 
maintained all these qualities to inhere in the blood, as 
heat inheres in boiling water or pottage,) and that the 
heart is the primary cause of pulsation and life ; to those 
persons, did I speak openly, I should say that I do not 
agree with the common opinion ; there are numerous 
particulars to be noted in the production of the parts 
of the body which incline me this way, but which it 
does not seem expedient to enter upon here. Before 
long, perhaps, I shall have occasion to lay before the 
world things that are more wonderful than these, and 
that are calculated to throw still greater light upon 
natural philosophy. 

Meantime I shall only say, and, without pretending 
to demonstrate it, propound — with the good leave of 
our learned men, and with all respect for antiquity — 
that the heart, with the veins and arteries and the 
blood they contain, is to be regarded as the beginning 
and author, and fountain and original of all things in the 
body, the primary cause of life ; and this in the same 
acceptation as the brain with its nerves, organs of sense 
and spinal marrow inclusive, is spoken of as the one 

Circulation of the Blood 167 

and general organ of sensation. But if by the word 
heart the mere body of the heart, made up of its auricles 
and ventricles, be understood, then I do not believe 
that the heart is the fashioner of the blood ; neither do 
I imagine that the blood has powers, propertii s, motion, 
or hcaU. Jl£_lh£-giIlv_o.f the heart ; lastly, neither do I 
admit that the cause of the systole and contraction is 
the same as that of the diastole or dilatation, whether 
in the arteries, auricles, or ventricles ; for I hold that 
that part of the pulse which is designated the diastole 
depends on another cause different from the systole, and 
that it must always and everywhere precede any systole ; 
I hold that the innate heat is the first cause of dilata- 
tion, and that the primary dilatation is in the blood 
itself, after the manner of bodies in a state of fermenta- 
tion, gradually attenuated and swelling, and that in the 
blood is this finally extinguished ; I assent to Aristotle's 
example of gruel or milk upon the fire, to this extent, 
that the rising and falling of the blood does not depend 
upon vapours or exhalations, or spirits, or anything 
rising in a vaporous or aereal shape, nor upon any 
external agency, but upon an internal principle under 
the control of nature. 

Nor is the heart, as some imagine, anything like a 
chauffer or fire, or heated kettle, and so the source ol 
the heat of the blood ; the blood, instead of receiving, 
rnthcj ^ivPsJ^^^ rr> the hearf^as'it does"TO"a11 the 
other parts of the body ; for the blood is the hottest 
element in the body ; and it is on this account that the 
heart is furnished with coronary arteries and veins ; it 
is for the same reason that other parts have vessels, 
viz. to secure the access of warmth for their due con- 
servation and stimulation ; so that the warmer any part 
is, the greater is its supply of blood, or otherwise ; 
where the blood is in largest quantity, there also is the 
heat highest. For this reason is the heart, remarkable 
through its cavities, to be viewed as the elaboratory, 
fountain, and perennial focus of heat, and as com- 

1 68 Circulation of the Blood 

parable to a hot kettle, not because of its proper 
substance, but because of its contained blood ; for the 
same reason, because they have numerous veins or 
vessels containing blood, are the liver, spleen, lungs, 
&c, reputed hot parts. And in this way do I view the 
native or innate heat as the common instrument of 
every function, the prime cause of the pulse among the 
rest. This, however, I do not mean to state absolutely, 
but only propose it by way of thesis. Whatever may 
be objected to it by good and learned men, without 
abusive or contemptuous language, I shall be ready to 
listen to — I shall even be most grateful to any one who 
will take up and discuss the subject. 

These, then, are, as it were, the very elements and 
indications of the passage and circulation of the blood, 
viz. from the right auricle into the right ventricle ; from 
the right ventricle by the way of the lungs into the left 
auricle; thence into the left ventricle and aorta; whence 
by the arteries at large through the pores or interstices 
of the tissues into the veins, and by the veins back 
again with great rapidity to the base of the heart. 

There is an experiment on the veins by which any- 
one that chooses may convince himself of this truth : 
Let the arm be bound with a moderately tight bandage. 
and then, by opening and shutting the hand, make all 
the veins to swell as much as possible, and the integu- 
ments below the fillets to become red ; and now let the 
arm and hand be plunged into very cold water, or snow, 
until the blood pent up in the veins shall have become 
cooled down ; then let the fillet be undone suddenly, 
and you will perceive, by the cold blood returning to 
the heart, with what celerity the current flows, and what 
an effect it produces when it has reached the heart ; so 
that you will no longer be surprised that some should 
faint when the fillet is undone after venesection. 1 This 
experiment shows that the veins swell below the 
ligature not with attenuated blood, or with blood raised 

1 Vide Chapter XI, of the Motion of the Heart, &c. 

Circulation of the Blood 169 

by spirits or vapours, for the immersion in the cold 
water would repress their ebullition, but with blood 
only, and such as could never make its way back into 
the arteries, either by open-mouthed communications 
or by devious passages ; it shows, moreover, how and 
in what way those who are travelling over snowy 
mountains are sometimes stricken suddenly with death, 
and other things of the same kind. 

1 . >t it should seem difficult for the blood to make- 
its way through the pores of the various structures of 
the body, I shall add one illustration : The same thing 
happens in the bodies of those that are hanged or 
strangled, as in the arm that is bound with a fillet : 
all the parts beyond the noose, — the face, lips, tongue, 
eyes, and every part of the head appear gorged with 
blood, swollen, and of a deep red or livid colour ; but 
if the noose be relaxed, in whatever position you have 
the body, before many hours have passed you will 
perceive the whole of the blood to have quitted the 
head and face, and gravitated through the pores of the 
skin, flesh, and other structures, from the superior parts 
towards those that are inferior and dependent, until 
they become tumid and of a dark colour. But if this 
happens in the dead body, with the blood dead and 
coagulated, the frame stiffened with the chill of death, 
the passages all compressed or blocked up, it is easy to 
perceive how much more apt it will be to occur in the 
living subject, when the blood is alive and replete with 
spirits, when the pores are all open, the fluid ready to 
penetrate, and the passage in every way made easy. 

When the ingenious and acute X>££cartes, (whose 
honourable mention of my name demands my acknow- 
ledgments,) and others, havingjaken out the hear: of a 
fish, and put it on a plate before them, see it continuing 
to pulsate (in contracting), and when it raises or erects 
itself and becomes firm to the touch, they think it 
enlarges, expands, and that its ventricles thence become 
more capacious. But, in my opinion, they do not 

i'/o Circulation of the Blood 

observe correctly ; for, at the time the heart gathers 
itself up, and becomes erect, it is certain that it is rather 
lessened in every one of its dimensions ; that it is in its 
systole, in short, not in its diastole. Neither, on the 
contrary, when it collapses and sinks down, is it then 
properly in its state of diastole and distension, by which 
the ventricles become more capacious. But as we do 
not say that the heart is in the state of diastole in the 
dead body, as having sunk relaxed after the systole, 
but is then collapsed, and without all motion — in short 
is in a state of rest, and not distended. It is only 
truly distended, and in the proper state of diastole, 
when it is filled by the charge of blood projected into 
it by the contraction of the auricles ; a fact which 
sufficiently appears in the course of vivisections. 
Descartes therefore does not perceive how much the 
relaxation and subsidence of the heart and arteries 
differ from their distension or diastole ; and that the 
cause of the distension, relaxation, and constriction, is 
not one and the same ; as contrary effects so must they 
rather acknowledge contrary causes ; as different move- 
ments they must have different motors ; just as all 
anatomists know that the flexion and extension of an 
extremity are accomplished by opposite antagonist 
muscles, and contrary or diverse motions are neces- 
sarily performed by contrary and diverse organs 
instituted by nature for the purpose. Neither do I 
find the efficient cause of the pulse aptly explained by 
this philosopher, when with Aristotle he assumes the 
cause of the systole to be the same as that of the 
diastole, viz. an effervescence of the blood due to a kind 
of ebullition. For the pulse is a succession of sudden 
strokes and quick percussions ; but we know of no kind 
of fermentation or ebullition in which the matter rises 
and falls in the twinkling of an eye ; the heaving is 
always gradual where the subsidence is notable. 
Besides, in the body of a living animal laid open, we 
can with our eyes perceive the ventricles of the heart 

Circulation of the Rlood 171 

both charged and distended by the contraction of the 
auricles, and more or less increased in size according 
to the charge ; and farther, we can see that the dis- 
tension of the heart is rather a violent motion, the effect 
of an impulsion, and not performed by any kind of 

Some are of opinion that, as no kind of impulse of 
the nutritive juices is required in vegetables, but that 
these are attracted by the parts which require them, 
and flow in to take the place of what has been lost ; so 
neither is there any necessity for an impulse in animals, 
the vegetative faculty in both working alike. But there 
is a difference between plants and animals. In animals, 
a constant supply of warmth is required to cherish the 
members, to maintain them in life by the vivifying heat, 
and to restore parts injured from without. It is not 
merely nutrition that has to be provided for. 

So much for the circulation ; any impediment, or 
perversion, or excessive excitement of which, is followed 
by a host of dangerous diseases and remarkable 
symptoms : in connexion with the veins — varices, 
abcesses, pains, hemorrhoids, hemorrhages ; in con- 
nexion with the arteries — enlargements, phlegmons, 
severe and lancinating pains, aneurisms, sarcoses, 
fluxions, sudden attacks of suffocation, asthmas, stupors, 
apoplexies, and innumerable other affections. But this 
is not the place to enter on the consideration of these ; 
neither may I say under what circumstances and how 
speedily some of these diseases, that are even reputed 
incurable, are remedied and dispelled, as if by en- 
chantment. I shall have much to put forth in my 
Medical Observations and Pathology, which, so far as 
I know, has as yet been observed by no one. 

That I may afford you still more ample satisfaction, 
most learned Riolanus, as you do not think there is a 
circulation in the vessels of the mesentery, I shall 
conclude by proposing the following experiment : 
throw a ligature round the porta close to the 

172 Circulation of the Blood 

liver, in a living animal, which is easily done. You 
will forthwith perceive the veins below the ligature 
swelling in the same way as those of the arm when the 
bleeding fillet is bound above the elbow ; a circum- 
stance which will proclaim the course of the blood 
there. And as you still seem to think that the blood 
can regurgitate from the veins into the arteries by open 
anastomoses, let the vena cava be tied in a living 
animal near the divarication of the crural veins, and 
immediately afterwards let an artery be opened to give 
issue to the blood : you will soon observe the whole of 
the blood discharged from all the veins, that of the 
ascending cava among the number, with the single 
exception of the crural veins, which will continue full ; 
and this certainly could not happen were there any 
retrograde passage for the blood from the veins to the 
arteries by open anastomoses. 




To Caspar Hofmanru Af.D. Published at Nurenberg y 
in the " Spicilegium Illustrium Epistolarum ad Casp. 

Your opinion of me, my most learned Hofmann, so 
candidly given, and of the motion and circulation of 
the blood, is extremely gratifying to me ; and I rejoice 
that I have been permitted to see and to converse with 
a man so learned as yourself, whose friendship I as 
readily embrace as I cordially return it. But I find 
that you have been pleased first elaborately to inculpate 
me, and then to make me pay the penalty, as having 
seemed to you " to have impeached and condemned 
Nature of folly and error ; and to have imputed to her 
the character of a most clumsy and inefficient artificer, 
in suffering the blood to become recrudescent, and 
making it return again and again to the heart in order 
to be reconcocted, to grow effete as often in the general 
system ; thus uselessly spoiling the perfectly-made blood, 
merely to find her in something to do. ; ' But where or 
when anything of the kind was ever said, or even 
imagined by me — by me, who, on the contrary, have 
never lost an opportunity of expressing my admiration 
of the wisdom and aptness and industry of Nature, — as 
you do not say, I am not a little disturbed to find such 
things charged upon me by a man of sober judgment 
like yourself. In my printed book, I do, indeed, assert 
that the blood is incessantly moving out from the heart 




by the arteries to the general system, and returning 

from this by the veins back to the heart, and with such 

an ebb and flow, in such mass and quantity that it 

must necessarily move in some way in a circuit. But 

if you will be kind enough to refer to my eighth and 

ninth chapters you will find it stated in so many words 

that I have purposely omitted to speak of the concoction 

of the blood, and of the causes of this motion and 

circulation, especially of the final cause. So much I 

have been anxious to say, that I might purge myself in 

the eyes of a learned and much respected man, — that I 

might feel absolved of the infamy of meriting such 

censure. And I beg you to observe, my learned, my 

impartial friend, if you would see with your own eyes 

the things I affirm in respect of the circulation, — and 

this is the course which most beseems an anatomist, — 

that I engage to comply with your wishes, whenever a 

fit opportunity is afforded ; but if you either decline 

this, or care not by dissection to investigate the subject 

for yourself, let me beseech you, I say, not to vilipend 

the industry of others, nor charge it to them as a 

crime; do not derogate from the faith of an honest 

man, not altogether foolish nor insane, who has had 

experience in such matters for a long series of years. 

Farewell, and beware ! and act by me, as I have done 
by you ; for what you have written I receive as uttered 
in all candour and kindness. Be sure, in writing to 
me in return, that you are animated by the same 

Niirnberg, May 20th, 1636. 


To Paul Marquard S/egel, of Hamburg 

I congratulate you much, most learned sir, on your 
excellent commentary, in which you have replied in a 
very admirable manner to Riolanus, the distinguished 

Letters 177 

anatomist, and, as you say, formerly your teacher : 
invincible truth has, indeed, taught the scholar to 
vanquish the master. I was myself preparing a sponge 
for his most recent arguments ; but intent upon my 
work " On the Generation of Animals " (which, but just 
(i>me forth, I send to you), I have not had leisure to 
produce it. And now I rather rejoice in the silence, 
as from your supplement I perceive that it has led you 
to come forward with your excellent reflections, to the 
common advantage of the world of letters. For I see 
that in your most ornate book (I speak without flattery), 
you have skilfully and nervously confuted all his 
machinations against the circulation, and successfully 
thrown down the scaffolding of his more recent opinions. 
I am, therefore, but little solicitous about labouring at 
any ulterior answer. Many things might, indeed, be 
adduced in confirmation of the truth, and several 
calculated to shed clearer light on the art of medicine ; 
but of these we shall perhaps see further by and by. 

Meantime, as Riolanus uses his utmost efforts to 
oppose the passage of the blood into the left ven- 
tricle through the lungs, and brings it all hither through 
the septum, and so vaunts himself upon having upset 
the very foundations of the Harveian circulation 
(although I have nowhere assumed such a basis for my 
doctrine ; for there is a circulation in many red-blooded 
animals that have no lungs), it may be well here to 
relate an experiment which I lately tried in the presence 
of several of my colleagues, and from the cogency of 
which there is no means of escape for him. Having 
tied the pulmonary artery, the pulmonary veins, and 
the aorta, in the body of a man who had been hanged, 
and then opened the left ventricle of the heart, we 
passed a tube through the vena cava into the right 
ventricle of the heart, and having, at the same time, 
attached an ox's bladder to the tube, in the same way 
as a clyster-bag is usually made, we filled it nearly full 
of warm water, and forcibly injected the fluid into the 
o 262 

1 7 8 


heart, so that the greater part of a pound of water was 
thrown into the right auricle and ventricle. The result 
was, that the right ventricle and auricle were enormously 
distended, but not a drop of water or of blood made 
its escape through the orifice in the left ventricle. The 
ligatures having been undone, the same tube was passed 
into the pulmonary artery, and a tight ligature having 
been put round it to prevent any reflux into the right 
ventricle, the water in the bladder was now pushed 
towards the lungs, upon which a torrent of the fluid, 
mixed with a quantity of blood, immediately gushed forth 
from the perforation in the left ventricle ; so that a 
quantity of water, equal to that which was pressed from 
the bladder into the lungs at each effort, instantly 
escaped by the perforation mentioned. You may try 
this experiment as often as you please ; the result you 
will still find to be as I have stated it. 

With this one experiment you may easily put an end 
to all Riolanus's altercations on the matter, to which 
he, nevertheless, so entirely trusts, that, without 
adducing so much as a single experiment in support of 
his views, he has been led to invent a new circulation, 
and even so far to commit himself as to say that, unless 
the old doctrine of the circulation x be overturned, his 
own is inadmissible. We may pardon this distinguished 
individual for not having sooner discovered a hidden 
truth ; but that he, so well skilled in anatomy as he is, 
should obstinately contend against a truth illustrated by 
the clearest light of reason, this surely is argument of 
his envy — let me not call it by any worse name. But, 
perhaps, we are still to find an excuse for Riolanus, 
and to say, that what he has written is not so much of 
his own motion, as in discharge of the duties of his 
office, and with a view to stand well with his colleagues. 
As Dean of the College of Paris, he was bound to see 
the physic of Galen kept in good repair, and to admit 
no novelty into the school, without the most careful 

i i.e. Harvey's Doctrine. 

Letters 179 

winnowing, lest, as he says, the precepts and dogmata 
of physic should be disturbed, and the pathology which 
has for so many years obtained the sanction of all the 
learned in assigning the causes of disease, be overthrown. 
1 1 has been playing the part of the advocate, therefore, 
rather than of the practised anatomist. But, as Aristotle 
tells us, it is not less absurd to expect demonstrative 
arguments from the advocate, than it is to look for 
persuasive arguments from the demonstrator or teacher. 
For the sake of the old friendship subsisting between 
us, moreover, and the high praise which he has lavished 
on the doctrine of the circulation, I cannot find it in 
my heart so say anything severe of Riolanus. 

I therefore return to you, most learned Slegel, and 
say, that I wish greatly I had been so full and explicit 
in what I have said on the subject of anastomosis in 
my disquisition to Riolanus, as would have left you 
with no doubts or scruples on the matter. I could 
wish, also, that you had taken into account not only 
what I have there denied, but likewise what I have- 
asserted on the transference of the blood from the 
arteries into the veins ; especially as I there seem to 
have pointed out some cause both for my inquiry and 
for my negation, to hint at a certain cause. I confess, 
I say, nay, I even pointedly assert, that I have never 
found any visible anastomoses. But this was particularly- 
said against Riolanus, who limited the circulation of 
the blood to the larger vessels only, with which, there- 
fore, these anastomoses, if any such there were, must 
have been made conformable, viz. of ample size, and 
distinctly visible. Although it be true, therefore, that 
I totally deny all anastomoses of this description — 
anastomoses in the way the word is commonly under- 
stood, and as the meaning has come down to us from 
Galen, viz. a direct conjunction between the orifices of 
the [visible] arteries and veins — I still admit, in the 
same disquisition, that I have found what is equivalent 
to this in three places, namely, in the plexus of the 

180 Letters 

brain, in the spermatic or preparing arteries and veins, 
and in the umbilical arteries and veins. I shall now, 
therefore, for your sake, my learned friend, enter some- 
what more at large into my reasons for rejecting the 
vulgar notion of the anastomoses, and explain my own 
conjectures concerning the mode of transition of the 
blood from the minute arteries into the finest veins. 

All reasonable medical men, both of ancient and 
modern times, have believed in a mutual transfusion, 
or accession and recession of the blood between the 
arteries and the veins ; and for the sake of permitting 
this, they have imagined certain inconspicuous openings, 
or obscure foramina, through which the blood flowed 
hither and thither, moving out of one vessel and re- 
turning to it again. Wherefore it is not wonderful that 
Riolanus should in various places find that in the 
ancients which is in harmony with the doctrine of a cir- 
culation. For a circulation in such sort teaches nothing 
more than that the blood flows incessantly from the veins 
into the arteries, and from the arteries back again into 
the veins. But as the ancients thought that this move- 
ment took place indeterminately, by a kind of accident, 
in one and the same place, and through the same 
channels, I imagine that they therefore found them- 
selves compelled to adopt a system of anastomoses, 
or fine mouths mutually conjoined, and serving both 
systems of vessels indifferently. But the circulation 
which I discovered teaches clearly that there is a 
necessary outward and backward flow of the blood, 
and this at different times and places, and through 
other and yet other channels and passages ; that this 
flow is determinate also, and for the sake of a certain 
end, and is accomplished in virtue of parts contrived 
for the purpose Avith consummate forecast and most 
admirable art. So that the doctrine of the motion of 
the blood from the veins into the arteries, which 
antiquity only understood in the way of conjecture, 
and which it also spoke of in confused and indefinite 

Letters 181 

terms, was laid down by me with its assured and 
necessary causes, and presents itself to the under- 
standing as a thing extremely clear, perfectly well 

arranged, and of approved verity. And then, when I 
perceived that the blood was transferred from the 
veins into the arteries through the medium of the 
heart with singular art, and with the aid of an admirable 
apparatus of valves, I imagined that the transference 
from the extremities of the arteries into those of the 
veins could not be effected without some other ad- 
mirable artifice, at least wherever there was no trans- 
udation through the pores of the flesh. I therefore 
held the anastomoses of the ancients as fairly open to 
suspicion, both as they nowhere presented themselves 
to our eyes, and as no sufficient reason was alleged for 
anything of the kind. 

Since, then, I find a transit from the arteries into the 
veins in the three places which I have above mentioned, 
equivalent to the anastomoses of the ancients, and even 
affording the farther security against any regurgitation 
into the arteries of the blood once delivered to the 
veins, and as a mechanism of such a kind is more 
elaborate and better suited to the circulation of the 
blood. I have therefore thought that the anastomoses 
imagined by the ancients were to be rejected. But 
you will ask, what is this artifice? what these ducts? 
viz. the small arteries, which are always much smaller — 
twice, even three times smaller — than the veins which 
they accompany, which they approach continually more 
and more, and within the tunics of which they are 
finally lost. I have been therefore led to conceive that 
the blood brought thus between the coats of the veins 
advanced for a certain way along them, and that the 
same thing took place here which we observe in the 
conjunction between the ureters and the bladder, and 
of the biliary duct with the duodenum. The ureters 
insinuate themselves obliquely and tortuously between 
the coats of the bladder, without anything in the 

1 82 Letters 

nature of an anastomosis, yet in such a manner as 
occasionally affords a passage to blood, to pus, and to 
calculi ; it is easy, moreover, to fill the bladder through 
them with air or water ; but by no effort can you force 
anything from the bladder into them. I care not, 
however, to make any question here of the etymology 
of words ; for I am not of opinion that it is the province 
of philosophy to infer aught as to the works of nature 
from the signification of words, or to cite anatomical 
disquisitions before the grammatical tribunal. Our 
business is not so much to inquire what a word properly 
signifies, as how it is commonly understood ; for use 
and wont as in so many other matters, are greatly 
to be considered in the interpretation of words. It 
seems to me, therefore, that we are to take especial 
care not to employ any unusual words, or any common 
ones already familiarly used, in a sense which is not in 
accordance with the meaning we purpose to attach to 
them. You indeed counsel well when you say, " only 
make sure of the thing, call it what you will." But 
when we discover that a thing has hitherto been in- 
differently or incorrectly explained (as the sequel will 
show it to have been in the present case), I do not 
think that the old appellation can ever be well applied 
to the new fact ; by using the old term you are apt to 
mislead where you desire to instruct. I acknowledge, 
then, a transit of the blood from the arteries into the 
veins, and that occasionally immediate, without any 
intervention of soft parts ; but it does not take place 
in the manner hitherto believed, and as you yourself 
would have it, where you say that anastomoses, correctly 
speaking, rather than an anastomosis, were required, 
namely, that the vessels may be open on either hand, 
and give free passage to the blood hither and thither. 
And hence it comes that you fail in the right solution 
of the question, when you ask how it happens that with 
the arteries as patent or pervious as the veins, the 
blood nevertheless flows only from the former into 

Letters 183 

the latter, never from the latter into the former? For 
what you say of the impulse of the blood through the 
arteries does not fully solve the difficulty in the present 
instance. For if the aorta be tied near the left ventricle 
of the heart in a Living animal, and all the blood 
removed from the arteries, the veins are still seen full 
of blood ; so that it neither moves back spontaneously 
into the arteries, nor can it be repelled into these by 
any force, whilst even in a dead animal it nevertheless 
falls of its own accord through the finest pores of the 
flesh and skin from superior into inferior parts. The 
passage of the blood into the veins is, indeed, effected 
by the impulse in question, and not by any dilatation 
of these in the manner of bellows, by which the blood 
is drawn towards them ; but there are no anastomoses 
of the vessels by conjunction (per copulam), in the way 
you mention, none where two vessels meeting are con- 
joined by equal mouths. There is only an opening of 
the artery into the vein, exactly in the same manner as 
the ureter opens into the bladder (and the biliary duct 
opens into the jejunum), by which, whilst the flow of 
urine is perfectly free towards the bladder, all reflux 
into the smaller conduits is effectually prevented ; the 
fuller the bladder is, indeed, the more are the sides of 
the ureters compressed, and the more effectual is all 
ascent of urine in them prevented. Now, on this 
hypothesis, it is easy to render a reason for the experi- 
ment which I have already mentioned. I add further, 
that I can in nowise admit such anastomoses as are 
commonly imagined, inasmuch as the arteries being 
always much smaller than the veins, it is impossible 
that their sides can mutually conjoin in such a way as 
will allow of their forming a common meatus ; it seems 
matter of necessity that things which join in this way 
should be of equal size. Lastly, these vessels having 
made a certain circuit, must, at their terminations, 
encounter one another ; they would not, as it happens, 
proceed straight to the extremities of the body. And 

1 84 


the veins, on their part, if they were conjoined with the 
arteries by mutual inosculations, would necessarily, and 
by reason of the continuity of parts, pulsate like the 

And now, that I may make an end of my writing, I 
say, that whilst I think the industry of every one de- 
serving of commendation, I do not remember that I 
have anywhere bepraised mine own. You, however, 
most excellent sir, I conceive have deserved high com- 
mendation, both for the care you have bestowed on 
your disquisition on the liver of the ox, and for the 
judgment you display in your observations. Go on, 
therefore, as you are doing, and grace the republic 
of letters with the fruits of your genius, for thus will 
you render a grateful service to all the learned, and 
especially to 

Your loving 

William Harvey. 

Written in London, this 26th of March, 165 1. 


To the very excellent John Nardi, of Florence 

I should have sent letters to you sooner, but our 
public troubles in part, and in part the labour of putting 
to press my work "On the Generation of Animals," 
have hindered me from writing. And indeed I, who 
receive your works — on the signal success of which 
I congratulate you from my heart — and along with 
them most kind letters, do but very little to one so 
distinguished as yourself in replying by a very short 
epistle. I only write at this time that I may tell you 
how constantly I think of you, and how truly I store up 
in my memory the grateful remembrance of all your 
kindnesses and good offices to myself and to my 

Letters 185 

nephew, when we were each of us severally in Florence. 
1 would wish, illustrious sir, to have your news as soon 
as convenient : — what you are about yourself, and what 
you think of this work of mine ; for I make no case of 
the opinions and criticisms of our pretenders to scholar- 
ship, who have nothing but levity in their judgments, 
and indeed are wont to praise none but their own 
productions. As soon as I know that you are well, 
however, and that you live not unmindful of us here, 
I propose to myself frequently to enjoy this intercourse 
by letter, and I shall take care to transmit other books 
to you. I pray for many and prosperous years to your 
Duke ; and for yourself a long (in/fiipia. Farewell, 
most learned sir, and love in return. 

Yours, most truly, 

William Harvey. 
The 15th oi July, 1651. 


In reply to R. Morison, M.D., of Paris 

Illustrious Sir, — The reason why your most kind 
letter has remained up to this time unanswered is 
simply this, that the book of M. Pecquet, upon which 
you ask my opinion, did not come into my hands until 
towards the end of the past month. It stuck by the 
way, I imagine, with some one, who, either through 
negligence, or desiring himself to see what was newest, 
has for so long a time hindered me of the pleasure 
I have had in the perusal. That you may, therefore, 
at once and clearly know my opinion of this work, 
I say that I greatly commend the author for his assiduity 
in dissection, for his dexterity in contriving new experi- 
ments, and for the shrewdness which he still evinces in 
his remarks upon them. With what labour do we 

1 86 Letters 

attain to the hidden things of truth when we take the 
averments of our senses as the guide which God has 
given us for attaining to a knowledge of his works ; 
avoiding that specious path on which the eyesight 
is dazzled with the brilliancy of mere reasoning, and so 
many are led to wrong conclusions, to probabilities 
only, and too frequently to sophistical conjectures on 
things ! 

I further congratulate myself on his confirmation of 
my views of the circulation of the blood by such lucid 
experiments and clear reasons. I only wish he had 
observed that the heart has three kinds of motion, 
namely, the systole, in which the organ contracts and 
expels the blood contained in its cavities, and next, 
a movement, the opposite of the former one, in which 
the fibres of the heart appropriated to motion are 
relaxed. Now these two motions inhere in the sub- 
stance of the heart itself, just as they do in all other 
muscles. The remaining motion is the diastole, in 
which the heart is distended by the blood impelled 
from the auricles into the ventricles ; and the ventricles, 
thus replete and distended, are stimulated to con- 
traction, and this motion always precedes the systole, 
which follows immediately afterwards. 

With regard to the lacteal veins discovered by Aselli, 
and by the further diligence of Pecquet, who discovered 
the receptacle or reservoir of the chyle, and traced the 
canals thence to the subclavian veins, I shall tell you 
freely, since you ask me what I think of them. I had 
already, in the course of my dissections, I venture 
to say even before Aselli had published his book, 1 
observed these white canals, and plenty of milk in 
various parts of the body, especially in the glands of 
younger animals, as in the mesentery, where glands 
abound ; and thence I thought came the pleasant 
taste of the thymus in the calf and lamb, which, as 
you know, is called the sweetbread in our vernacular 

1 Published at Milan in 1622. 

Letters 187 

gue. But for various reasons, and led by several 
experiments, I could never be brought to believe that 
that milky fluid was chyle conducted hither from the 
intestines, and distributed to all parts of the body for 
their nourishment ; but that it was rather nut with 
occasionally and by accident, and proceeded from too 
ample a supply of nourishment and a peculiar vigour of 
concoction ; in virtue of the same law of nature, in 
short, as that by which fat, marrow, semen, hair, &c, 
are produced ; even as in the due digestion of ulcers 
pus is formed, which the nearer it approaches to the 
consistency of milk, viz. as it is whiter, smoother, and 
more homogeneous, is held more laudable, so that 
some of the ancients thought pus and milk were of the 
same nature, or nearly allied. Wherefore, although 
there can be no question of the existence of the vessels 
themselves, still I can by no means agree with Aselli in 
considering them as chyliferous vessels, and this especi- 
ally for the reasons about to be given, which lead me to 
a different conclusion. For the fluid contained in the 
lacteal veins appears to me to be pure milk, such as is 
found in the lacteal veins [the milk ducts] of the 
mammae. Now it does not seem to me very probable 
(any more than it does to Auzotius in his letter to 
Pecquet) that the milk is chyle, and thus that the 
whole body is nourished by means of milk. The 
reasons which lead to a contrary conclusion, viz. that 
it is chyle, are not of such force as to compel my 
assent. I should first desire to have it demonstrated to 
me by the clearest reasonings, and the guarantee of 
experiments, that the fluid contained in these vessels 
was chyle, which, brought hither from the intestines, 
supplies nourishment to the whole body. For unless 
we are agreed upon the first point, any ulterior, any 
more operose, discussion of their nature, is in vain. 
But how can these vessels serve as conduits for the 
whole of the chyle, or the nourishment of the body, 
when we see that they are different in different animals ? 

1 88 Letters 

In some they proceed to the liver, in others to the 
porta only, and in others still to neither of these. In 
some creatures they are seen to be extremely numerous 
in the pancreas ; in others the thymus is crowded with 
them ; in a third class, again, nothing can be seen of 
them in either of these organs. In some animals, 
indeed, such chyliferous canals are nowhere to be dis- 
covered (vide Liceti Epist. xiii, tit. ii, p. 83, et Sen- 
nerti Praxeos, lib. v, tit. 2, par. 3, cap. 1); neither do 
they exist in any at all times. But the vessels which 
serve for nutrition must necessarily both exist in all 
animals, and present themselves at all times ; inasmuch 
as the waste incurred by the ceaseless efflux of the 
spirits, and the wear and tear of the parts of the body, 
can only be supplied by as ceaseless a restoration or 
nutrition. And then, their very slender calibre seems 
to render them not less inadequate to this duty than 
their structure seems to unfit them for its performance: 
the smaller channels ought plainly to end in larger 
ones, these in their turn in channels larger still, and the 
whole to concentrate in one great trunk, which should 
correspond in its dimensions to the aggregate capacity 
of all the branches ; just such an arrangement as may 
be seen to exist in the vena portse and its tributaries, 
and farther in the trunk of the tree, which is equal 
to its roots. Wherefore, if the efferent canals of a fluid 
must be equal in dimensions to the afferent canals 
of the same fluid, the chyliferous ducts which Pecquet 
discovers in the thorax ought at least to equal the two 
ureters in dimensions ; otherwise they who drink a 
gallon or more of one of the acidulous waters could not 
pass off all this fluid in so short a space of time by 
these vessels into the bladder. And truly, when we 
see the matter of the urine passing thus copiously 
through the appropriate channels, I do not see how 
these veins could preserve their milky colour, and the 
urine all the while remain without a tinge of whiteness. 
I add, too, that the chyle is neither in all animals, 

Letters 189 

nor at all times, of the consistency and colour of milk ; 
and therefore did these vessels carry chyle, they could 
not always (which nevertheless they do) contain a white 
fluid in their interior, but would sometimes be coloured 
yellow, green, or of some other hue (in the same way 
as the urine is affected, and acquires different colours 
from eating rhubarb, asparagus, rigs, &c.) ; or otherwise, 
when large quantities of mineral water were drunk, they 
would be deprived of almost all colour. Besides, did 
that white matter pass from the intestines into those 
canals, or were it attracted from the intestines, the 
same fluid ought certainly to be discovered somewhere 
within the intestines themselves, or in their spongy 
tunics ; for it does not seem probable that any fluid by 
bare and rapid percolation of the intestines could 
assume a new nature, and be changed into milk. 
Moreover, were the chyle only filtered through the 
tunics of the intestines, it ought surely to retain some 
traces of its original nature, and resemble in colour and 
smell the fluid contained in the intestines ; it ought to 
smell offensively at least; for whatever is contained 
in the intestines is tinged with bile, and smells un- 
pleasantly. Some have consequently thought that the 
body was nourished by means of chyle raised into 
attenuated vapour, because vapours exhaling in the 
alembic, even from fcetid matters, often do not smell 

The learned Pecquet ascribes the motion of this 
milky fluid to respiration. For my own part, though 
strongly tempted to do otherwise, I shall say nothing 
upon this topic until we are agreed as to what the fluid 
is. But were we to concede the point (which Pecquet 
takes for granted without any sufficient reason in the 
shape of argument), that chyle was continually trans- 
ported by the canals in question from the intestines to 
the subclavian veins, in which the vessels he has lately- 
discovered terminate, w r e should have to say that the 
chyle before reaching the heart was mixed with the 

1 90 Letters 

blood which is about to enter the right side of the organ, 
and that it there obtains a further concoction. But 
what, some one might with as good reason ask, should 
hinder it from passing into the porta, then into the liver, 
and thence into the cava, in conformity with the arrange- 
ment which Aselli and others are said to have found ? 
Why, indeed, should we not as well believe that the 
chyle enters the mouths of the mesenteric veins, and in 
this way becomes immediately mingled with the blood, 
where it might receive digestion and perfection from 
the heat, and serve for the nutrition of all the parts ? 
For the heart itself can be accounted of higher import- 
ance than other parts, can be termed the source of 
heat and of life, upon no other grounds than as it 
contains a larger quantity of blood in its cavities, 
where, as Aristotle says, the blood is not contained 
in veins as it is in other parts, but in an ample sinus 
and cistern, as it were. And that the thing is so in 
fact, I find an argument in the distribution of innumer- 
able arteries and veins to the intestines, more than to 
any other part of the body, in the same way as the 
uterus abounds with blood-vessels during the period of 
pregnancy. For nature never acts inconsiderately. In 
all the red-blooded animals, consequently, which require 
[abundant] nourishment, we find a copious distribution 
of mesenteric vessels ; but lacteal veins we discover in 
but a few, and even in these not constantly. Where- 
fore, if we are to judge of the uses of parts as we meet 
with them in general and in the greater number of 
animals, beyond all doubt those filaments of a white 
colour, and very like the fibres of a spider's web, are 
not instituted for the purpose of transporting nourish- 
ment, neither is the fluid they contain to be designated 
by the name of chyle ; the mesenteric vessels are rather 
destined to the duty in question. Because, of that 
whence an animal is constituted, by that must it neces- 
sarily grow, and by that consequently be nourished ; for 
the nutritive and augmentative faculties, or nutrition 

Letters 191 

and growth, are essentially the same. An animal, 
therefore, naturally grows in the same manner as it 
receives immediate nutriment from the first. Now 
it is a most certain fact (as I have shown elsewhere) 
that the embryos of all red-blooded animals are 
nourished by means of the umbilical vessels from 
the mother, and this in virtue of the circulation of 
the blood. They are not nourished, however, imme- 
diately by the blood, as many have imagined, but after 
the manner of the chick in ovo, which is first nourished 
by the albumen, and then by the vitellus, which is 
finally drawn into and included within the abdomen 
of the chick. All the umbilical vessels, however, are 
inserted into the liver, or at all events pass through it, 
even in those animals whose umbilical vessels enter the 
vena porta?, as in the chick, in which the vessels proceed- 
ing from the yelk always so terminate. In the selfsame 
way, therefore, as the chick is nourished from a 
nutriment, (viz. the albumen and vitellus,) previously 
prepared, even so does it continue to be nourished 
through the whole course of its independent existence. 
And the same thing, as I have elsewhere shown, is 
common to all embryos whatsoever : the nourishment, 
mingled with the blood, is transmitted through their 
veins to the heart, whence moving on by the arteries, 
it is carried to every part of the body. The fcetus 
when born, when thrown upon its own resources, and 
no longer immediately nourished by the mother, makes 
use of its stomach and intestines just as the chick 
makes use of the contents of the egg, and vegetables 
make use of the ground whence they derive concocted 
nutriment. For even as the chick at the commence- 
ment obtained its nourishment from the egg, by means 
of the umbilical vessels (arteries and veins) and the 
circulation of the blood, so does it subsequently, and 
when it has escaped from the shell, receive nourishment 
by the mesenteric veins ; so that in either way the chy!e 
passes through the same channels, and takes its route 

192 Letters 

by the same path through the liver. Nor do I see any 
reason why the route by which the chyle is carried in 
one animal should not be that by which it is carried 
in all animals whatsoever ; nor indeed, if a circulation 
of the blood be necessary in this matter, as it really is, 
that there is any need for inventing another way. 

I must say that I greatly prize the industry of the 
learned Pecquet, and make much of the receptacle 
which he has discovered ; still it does not present itself 
to me as of such importance as to force me from the 
opinion I have already given ; for I have myself found 
several receptacles of milk in young animals ; and in 
the human embryo I have found the thymus so dis- 
tended with milk, that suspicions of an imposthume 
were at first sight excited, and I was disposed to believe 
that the lungs were in a state of suppuration, for the 
mass of the thymus looked actually larger than the 
lungs themselves. Frequently, too, I have found a 
quantity of milk in the nipples of new-born infants, 
as also in the breasts of young men who were very 
lusty. I have also met with a receptacle full of milk in 
the body of a fat and large deer, in the situation where 
Pecquet indicates his receptacle, of such a size that 
it might readily have been compared to the abomasus, 
or read of the animal. 

These observations, learned sir, have I made at this 
time in answer to your letter, that I might show my 
readiness to comply with your wishes. 

Pray present my most kind wishes to Dr. Pecquet 
and to Dr. Gayant. Farewell, and believe me to be, 
very affectionately and respectfully, 


William Harvey. 

London, the 2Sth April, 1652. 

Letters 193 


To the most excellent and learned John Nardi, 
of Florence 

Distinguished and accomplished Sir, — The arrival 
of your letter lately gave me the liveliest pleasure, and 
the receipt at the same time of your learned comments 
upon Lucretius satisfied me that you are not only living 
and well, but that you arc at work among the sacred 
things of Apollo. I do indeed rejoice to see truly 
learned men everywhere illustrating the republic of 
letters, even in the present age, in which the crowd 
of foolish scribblers is scarcely less than the swarms of 
flies in the height of summer, and threatens with their 
crude and flimsy productions to stifle us as with smoke. 
Among other things that delighted me greatly in your 
book was that part where I see you ascribe plague 
almost to the same efficient cause as I do animal 
generation. Still it must be confessed that it is difficult 
to explain how the idea, or form, or vital principle 
should be transfused from the genitor to the genetrix, 
and from her transmitted to the conception or ovum, 
and thence to the foetus, and in this produce not only 
an image of the genitor, or an external species, but also 
various peculiarities or accidents, such as disposition, 
vices, hereditary diseases, naevi or mother-marks, &c. 
All of these accidents must inhere in the geniture and 
semen, and accompany that specific thing, by whatever 
name you call it, from which an animal is not only 
produced, but by which it is afterwards governed, and 
to the end of its life preserved. As all this, I say, is 
not readily accounted for, so do I hold it scarcely less 
difficult to conceive how pestilence or leprosy should be 
communicated to a distance by contagion, by a zymotic 
element contained in woollen or linen things, household 
furniture, even the walls of a house, cement, rubbish, 
p 262 

194 Letters 

&c, as we find it stated in the fourteenth chapter of 
Leviticus. How, I ask, can contagion, long lurking in 
such things, leave them in fine, and after a long lapse of 
time produce its like in another body ? Nor in one or 
two only, but in many, without respect of strength, 
sex, age, temperament, or mode of life, and with such 
violence that the evil can by no art be stayed or 
mitigated. Truly it does not seem less likely that 
form, or soul, or idea, whether this be held substan- 
tive or accidental, should be transferred to something 
else, whence an animal at length emerges, all as if it 
had been produced on purpose, and to a certain end, 
with foresight, intelligence, and divine art. 

These are among the number of more abstruse 
matters, and demand your ingenuity, most learned 
Nardi. Nor need you plead in excuse your advanced 
life; I myself, although verging on my eightieth year, 
and sorely failed in bodily strength, nevertheless feel 
my mind still vigorous, so that I continue to give my- 
self up with the greatest pleasure to studies of this kind. 
I send you along with these, three books upon the sub- 
ject you name. 1 If you will mention my name to his 
Serene Highness the Duke of Tuscany, with thankful- 
ness for the distinguished honour he did me when I 
was formerly in Florence, and add my wishes for 
his safety and prosperity, you will do a very kind 
thing to 

Your devoted and very attached friend, 

William Harvey. 

30th Nov. 1653. 

[' Nardi had written to Harvey requesting him to select a few of the 
publications which should give a faithful narrative of the distractions 
that had but lately agitated England.] 

Letters 195 


To John Daniel Ilorst, principal Physician of 

Excellent Sir, — I am much pleased to find, that 
in spite of the long time that has passed, and the dis- 
tance that separates us, you have not yet lost me from 
your memory, and I could wish that it lay in my power 
to answer all your inquiries. But, indeed, my age does 
not permit me to have this pleasure, for I am not only 
far stricken in years, but am afflicted with more and 
more indifferent health. With regard to the opinions 
of Riolanus, and his decision as to the circulation of 
the blood, it is very obvious that he makes vast throes 
in the production of vast trifles; nor do I see that he 
has as yet satisfied a single individual with his figments. 
Slegel wrote well and modestly, and, had the fates 
allowed, would undoubtedly have answered his argu- 
ments and reproaches also. But Slegel as I learn, and 
grieve to learn, died some months ago. As to what 
you ask of me, in reference to the so-called lacteal 
veins and thoracic ducts, I reply, that it requires good 
eyes, and a mind free from other anxieties, to come to 
any definite conclusion in regard to these extremely 
minute vessels; to me, however, as 1 have just said, 
neither of these requisites is given. About two years 
ago, when asked my opinion on the same subject, I 
replied at length, and to the effect that it was not 
sufficiently determined whether it was chyle or one of 
the thicker constituents of milk, destined speedily to 
pass into fat, which flowed in these white vessels ; and 
further that the vessels themselves are wanting in several 
animals, namely, birds and fishes, though it seems most 
probable that these creatures are nourished upon the 
same principles as quadrupeds ; nor can any sufficient 
reason be rendered why in the embryo all nutriment, 



carried by the umbilical vein, should pass through the 
liver, but that this should not happen when the foetus 
is freed lrom the prison of the womb, and made inde- 
pendent. Besides, the thoracic duct itself, and the 
orifice by which it communicates with the subclavian 
vein, appear too small and narrow to suffice for the 
transmission of all the supplies required by the body. 
And I have asked myself farther, why such numbers of 
blood-vessels, arteries, and veins should be sent to the 
intestines if there were nothing to be brought back 
from thence? especially as these are mere membraneous 
parts, and on this account require a smaller supply of 

These and other observations of the same tenor I 
have already made, — not as being obstinately wedded 
to my own opinion, but that I might find out what 
could reasonably be urged to the contrary by the 
advocates of the new views. I am ready to award 
the highest praise to Pecquet and others for their 
singular industry in searching out the truth ; nor do 
I doubt but that many things still lie hidden in 
Democritus's well that are destined to be drawn up 
into the light by the indefatigable diligence of coming 
ages. So much do I say at this time, which, I trust, 
with your known kindness, you will take in good part. 
Farewell, learned friend; live happily, and hold me 

Yours, most affectionately, 

William Harvey. 

London, 1st February, 1654-5. 

Letters 197 


To the distinguished and /earned John Dan. Horst, 
principal Physician at the Court of Hesse- Darmstadt 

Most EXCELLENT Sir, — Advanced age, which unfits 
us for the investigation of novel subtleties, and the 
mind which inclines to repose after the fatigues of 
lengthened labours, prevent me from mixing myself 
up with the investigation of these new and difficult 
questions : so far am I from courting the office of 
umpire in this dispute ! I was anxious to do you a 
pleasure lately, when, in reply to your request, I sent 
you the substance of what I had formerly written to a 
Parisian physician as my ideas on the lacteal veins and 
thoracic ducts. 1 Not, indeed, that I was certain of the 
opinion then delivered, but that I might place these 
objections such as they were before those who fancy 
that when they have made a certain progress in discovery 
all is revealed by them. 

With reference to your letters in reply, however, and 
in so far as the collection of milky fluid in the vessels 
of Aselli is concerned, 1 have not ascribed it to accident, 
and as if there were not certain assignable causes for its 
existence ; but I have denied that it was found at all 
times in all animals, as the constant tenor of nutrition 
would seem to require. Nor is it requisite that a matter, 
already thin and much diluted, and which is to become 
fat after the ulterior concoction, should concrete in the 
dead animal. The instance of pus, I have adduced only 
incidentally and collaterally. The hinge upon which our 
whole discussion turns is the assumption that the fluid 
contained in the lacteal vessels of Aselli is chyle. This 
position I certainly do not think you demonstrate satis- 
factorily, when you say that chyle must be educed from 

[' Pecquet described the duct as dividing into two branches, one for 
e-»ch subclavian vein.] 



the intestines, and that it can by no means be carried 
off by the arteries, veins, or nerves ; and thence conclude 
that this function must be performed by the lacteals. 
I, however, can see no reason wherefore the innumer- 
able veins which traverse the intestines at every point, 
and return to the heart the blood which they have 
received from the arteries, should not, at the same 
time, also suck up the chyle which penetrates the parts, 
and so transmit it to the heart ; and this the rather, as 
it seems probable that some chyle passes immediately 
from the stomach before its contents have escaped into 
the intestines, (or how account for the rapid recovery of 
the spirits and strength in cases of fainting ?) although 
no lacteals are distributed to the stomach. 

With regard to the letter which you inform me you 
have addressed to Bartholin, I do not doubt of his 
replying to you as you desire ; nor is there any occasion 
wherefore I should trouble you farther on that topic. 
I only say (keeping silence as to any other channels), 
that the nutritive juice might be as readily transported 
by the uterine arteries, and distilled into the uterus, 
as watery fluid is carried by the emulgent arteries 
to the kidneys. Nor can this juice be spoken of as 
preternatural ; neither ought it to be compared to the 
vagitus uterinus, seeing that in pregnant women the 
fluid is always present, the vagitus an incident of very 
rare occurrence. What you say of the excrements of 
new-born infants differing from those of the child that 
has once tasted milk I do not admit ; for except in the 
particular of colour, I scarcely perceive any difference 
between them, and conceive that the black hue may 
fairly be ascribed to the long stay of the fasces in the 

Your proposal that I should attempt a solution of 
the true use of these newly-discovered ducts, is an 
undertaking of greater difficulty than comports with the 
old man far advanced in years, and occupied with other 
cares : nor can such a task be well entrusted to several 

Letters 199 

hands, were even such assistance as you indicate at my 
command 1 ; but it is not; Highmore does not live in 
our neighbourhood, and I have not seen him f 
period of some seven years. So much I write at present, 
most learned sir, trusting it will he taken in good part 
as coming from yours, 

Wry sincerely and respectfully, 

William Harvey. 

London, 13th July, 1655 (old style). 


To the very learned John Xardi, of Florence, a man 
distinguished alike for his virtues, life, and erudition 

Mosi excellent Sir, — I lately received your 
most agreeable letter, from which I am equally de- 
lighted to learn that you are well, that you go on 
prosperously, and labour strenuously in our chosen 
studies. But I am not informed whether my letter in 
reply to yours, along with a few books forwarded at the 
same time, have come to hand or not. I should be 
happy to have news on this head at your earliest con- 
venience, and also to be made acquainted with the 
progress you make in your " Noctes Geniales," and 
other contemplated works. For I am used to solace 
my declining years, and to refresh my understanding, 
jaded with the trifles of every-day life, by reading the 
best works of this description. I have again to return 
you my best thanks for your friendly offices to my 
nephew when at Florence in former years ; and on the 
arrival in Italy of another of my nephews (who is the 

[' Horst, in the letter to which the above is an answer, had said, 
" Xobilissime Harveie, &c. Most noble Harvey, I only wish \ou could 
snatch the leisure to explain to the world the true use of these lymphatic 
and thoracic ducts. You have many illustrious scholars, particularly 
Highmore, with whose assistance it were easy to solve all doubts."] 

200 Letters 

bearer of this letter), I entreat you very earnestly that 
you will be pleased most kindly to favour him with any 
assistance or advice of which he may stand in need. 
For thus will you indeed do that which will be very 
gratifying to me. Farewell, most accomplished sir, and 
deign to cherish the memory of our friendship, as does 
most truly the admirer of all your virtues, 

William Harvey. 

London, Oct. 25th, in the year of the Christian era, 1655. 


To the distinguished and accomplished John Vlackveld, 
Physician at Harlem 

Learned Sir, — Your much esteemed letter reached 
me safely, in which you not only exhibit your kind 
consideration of me, but display a singular zeal in the 
cultivation of our art. 

It is even so. Nature is nowhere accustomed more 
openly to display her secret mysteries than in cases 
where she shows traces of her workings apart from the 
beaten path ; nor is there any better way to advance 
the proper practice of medicine than to give our minds 
to the discovery of the usual law of nature, by the 
careful investigation of cases of rarer forms of disease. 
For it has been found in almost all things, that what 
they contain of useful or of applicable, is hardly per- 
ceived unless we are deprived of them, or they become 
deranged in some way. The case of the plasterer x to 
which you refer is indeed a curious one, and might 
supply a text for a lengthened commentary by way of 

[' Valkveld bad sent to Harvey the particulars of a case of diseased 
bladder, in which that viscus was found after death not larger than " a 
wainut with the husk,'' its walls as thick as the thickness of the little 
finger, and its inner suiface ulcerated.] 

Letters 20 1 

illustration. But it is in vain that you apply the spur 
to urge me, at my present age, not mature merely but 
declining, to gird myself for any new investigation. 
For I now consider myself entitled to my discharge 
from duty. It will, however, always he a pleasant sight 
for me to see distinguished men like yourself engaged 
in this honorable arena. Farewell, most learned sir, 
and whatever you do, still love 

Yours, most respectfully, 

William Harvey. 

London, 24th April, 1657. 














[This account first appeared in the work of Dr. Betts, entitled : 
"De Ortu et Natura Sanguinis," 8vo, London, 1669, the MS. 
having been presented to Betts by Mr. Michael Harvey, nephew 
of the author, with whom Betts was on terms of intimacy.] 




S S, 



S> y 


(m[ LIBRARY]*] 



Thomas Parr, a poor countryman, born near 
VVinnington, in the county of Salop, died on the 14th 
of November, in the year of grace 1635, after having 
lived one hundred and fifty-two years and nine months, 
and survived nine princes. This poor man, having 
been visited by the illustrious Earl of Arundel when 
he chanced to have business in these parts, (his lord- 
ship being moved to the visit by the fame of a thing 
so incredible,) was brought by him from the country to 
London ; and, having been most kindly treated by the 
earl both on the journey and during a residence in his 
own house, was presented as a remarkable sight to his 
Majesty the King. 

Having made an examination of the body of this 
aged individual, by command of his Majesty, several 
of whose principal physicians were present, the following 
particulars were noted : 

The body was muscular, the chest hairy, and the 
hair on the fore-arms still black ; the legs, however, 
were without hair, and smooth. 

The organs of generation were healthy, the penis 
neither retracted nor extenuated, nor the scrotum filled 
with any serous infiltration, as happens so commonly 
among the decrepid ; the testes, too, were sound and 
large ; so that it seemed not improbable that the 
common report was true, viz. that he did public 
penance under a conviction for incontinence, after he 
had passed his hundredth year ; and his wife, whom 


208 Anatomical Examination 

he had married as a widow in his hundred-and-twentieth 
year, did not deny that he had intercourse with her 
after the manner of other husbands with their wives, 
nor until about twelve years back had he ceased to 
embrace her frequently. 

The chest was broad and ample ; the lungs, nowise 
fungous, adhered, especially on the right side, by 
fibrous bands to the ribs. They were much loaded 
with blood, as we find them in cases of peripneumony, 
so that until the blood was squeezed out they looked 
rather blackish. Shortly before his death I had ob- 
served that the face was livid, and he suffered from 
difficult breathing and orthopnoea. This was the reason 
why the axillae and chest continued to retain their heat 
long after his death : this and other signs that present 
themselves in cases of death from suffocation were 
observed in the body. 

We judged, indeed, that he had died suffocated, 
through inability to breathe, and this view was confirmed 
by all the physicians present, and reported to the King. 
When the blood was expressed, and the lungs were 
wiped, their substance was beheld of a white and 
almost milky hue. 

The heart was large, and thick, and fibrous, and 
contained a considerable quantity of adhering fat, both 
in its circumference and over its septum. The blood 
in the heart, of a black colour, was dilute, and scarcely 
coagulated ; in the right ventricle alone some small 
clots were discovered. 

In raising the sternum, the cartilages of the ribs were 
not found harder or converted into bone in any greater 
degree than they are in ordinary men ; on the contrary, 
they were soft and flexible. 

The intestines were perfectly sound, fleshy, and 
strong, and so was the stomach : the small intestines 
presented several constrictions, like rings, and were 
muscular. Whence it came that, by day or night, 
observing no rules or regular times for eating, he was 

of Thomas Parr 209 

y to discuss any kind of eatable was at hand ; 
his ordinary diet consisting of sub-rancid cheese, and 
milk in every form, coarse and hard bread, and small 
drink, generally sour whey. On this sorry fare, but 
living in his home, free from care, did this poor man 
attain to such length of days. He even ate something 
about midnight shortly before his death. 

The kidneys were bedded in fat, and in themselves 
sufficiently healthy ; on their anterior aspects, however, 
they contained several small watery abscesses or serous 
collections, one of which, the size of a hen's egg, con- 
taining a yellow fluid in a proper cyst, had made a 
rounded depression in the substance of the kidney. 
To this some were disposed to ascribe the suppression 
of urine under which the old man had laboured shortly 
before his death ; whilst others, and with greater show 
of likelihood, ascribed it to the great regurgitation of 
serum upon the lungs. 

There was no appearance of stone either in the 
kidneys or bladder. 

The mesentery was loaded with fat, and the colon, 
with the omentum, which was likewise fat, was attached 
to the liver, near the fundus of the gall-bladder ; in 
like manner the colon was adherent from this point 
posteriorly with the peritoneum. 

The viscera were healthy : they only looked some- 
what white externally, as they would have done had 
they been parboiled ; internally they were (like the 
blood) of the colour of dark gore. 

The spleen was very small, scarcely equalling one of 
the kidneys in size. 

All the internal parts, in a word, appeared so healthy, 
that had nothing happened to interfere with the old 
man's habits of life, he might perhaps have escaped 
paying the debt due to nature for some little time 

The cause of death seemed fairly referrible to a 
sudden change in the non-naturals, the chief mischief 

Q 262 

210 Anatomical Examination 

being connected with the change of air, which through 
the whole course of life had been inhaled of perfect 
purity, — light, cool, and mobile, whereby the pnecordia 
and lungs were more freely ventilated and cooled ; but 
in this great advantage, in this grand cherisher of life 
this city is especially destitute ; a city whose grand 
characteristic is an immense concourse of men and 
animals, and where ditches abound, and filth and offal 
lie scattered about, to say nothing of the smoke 
engendered by the general use of sulphureous coal 
as fuel, whereby the air is at all times rendered heavy, 
but much more so in the autumn than at any other 
season. Such an atmosphere could not have been 
found otherwise than insalubrious to one coming from 
the open, sunny, and healthy region of Salop ; it must 
have been especially so to one already aged and infirm. 

And then for one hitherto used to live on food 
unvaried in kind, and very simple in its nature, to be 
set at a table loaded with variety of viands, and tempted 
not only to eat more than wont, but to partake of strong 
drink, it must needs fall out that the functions of all 
the natural organs would become deranged. Whence 
the stomach at length failing, and the excretions long 
retained, the work of concoction proceeding languidly, 
the liver getting loaded, the blood stagnating in the 
veins, the spirits frozen, the heart, the source of life, 
oppressed, the lungs infarcted, and made impervious 
to the ambient air, the general habit rendered more 
compact, so that it could no longer exhale or perspire 
— no wonder that the soul, little content with such a 
prison, took its flight. 

The brain was healthy, very firm and hard to the 
touch ; hence, shortly before his death, although he 
had been blind for twenty years, he heard extremely 
well, understood all that was said to him, answered 
immediately to questions, and had perfect apprehension 
of any matter in hand ; he was also accustomed to walk 
about, slightly supported between two persons. His 

of Thomas Parr 21 1 

memory, however, was greatly impaired, so that he 
scarcely recollected anything of what had happened 
to him when he was a young man, nothing of public 
incidents, or of the kings or nobles who had made a 
figure, or of the wars or troubles of his earlier life, or 
of the manners of society, or of the prices of things — 
in a word, of any of the ordinary incidents which men 
are wont to retain in their memories. He only recol- 
lected the events of the last few years. Nevertheless, 
he was accustomed, even in his hundred and thirtieth 
year, to engage lustily in every kind of agricultural 
labour, whereby he earned his bread, and he had 
even then the strength required to thrash the corn. 


Extracted from the Registry of the Prerogative Court 

of Canterbury 

In the name of the Almighty and Eternal God 
Amen I William Harvey of London Doctor of 
Physicke doe by these presents make and ordaine this 
my last Will and testament in manner and forme 
following Revoking hereby all former and other wills 
and testaments whatsoever Imprimis I doe most 
humbly render my soule to Him that gave it and to 
my blessed Lord and Saviour Christ Jesus and my 
bodie to the Earth to be buried at the discretion of 
my executor herein after named The personall estate 
which at the time of my decease I shalbe in any way 
possessed of either in Law or equitie be it in goods 
householdstuffe readie moneys debts duties arrearages 
of rents or any other wayes whatsoever and whereof I 
shall not by this present will or by some Codicill to 
be hereunto annexed make a particular gift and dis- 
position I doe after my debts Funeralls and Legacies 
paid and discharged give and bequeath the same 
vnto my loving brother Mr. Eliab Harvey merchant 
of London whome I make Executor of this my last 
will and testament And whereas I have lately pur- 
chased certaine lands in Northamptonshire or there- 
abouts commonly knoivne by the name of Oxon 
grounds and formerly belonging vnto to the Earl of 
Manchester and certaine other grounds in Leicester- 
shire commonly called or knowne by the name of 


The Will of Harvey 213 

T.aron Parke and sometime heretofore belonging vnto 
Sir Henry Hastings Knight both which purchases were 
made in the name of several persons nominated 
and trusted by me and by two several] deeds of 
declaracon vnder the handes and seales of all persons 
any wave parties or privies to the said trusts are 
declared to be rirst vpon trust and to the intent that 
I should be permitted to enioye all the rents and 
profits and the benefit of the collaterall securitie during 
my life and from and after my decease Then upon 
trust and for the benefit of such person and persons 
and of and for such estate and estates and Interests 
And for raysing and payment of such summe and 
summes of Money Rents Charges Annuities and yearly 
payments to and for such purposes as from time to 
time by any writing or writings to be by me signed 
and sealed in the presence of Two or more credible 
witnesses or by my last will and testament in writing 
should declare limit direct or appoint And further in 
trust that the said Mannors and lands and everie part 
thereof together with the Collaterall securitie should 
be assigned conveyed and assured vnto such persons 
and for suche Estates as the same should by me be 
limited and directed charged and chargeable never- 
theles with all Annuities rents and summes of money 
by me limited and appointed if any such shalbe And 
in default of such appointment then to Eliab Harvey 
his heires executors and Assignes or to such as he 
or they shall nominate as by the said two deeds of 
declaracon both of them bearing date the tenth day 
of July in the year of our Lord God one Thousand 
sixe hundred Fiftie and one more at large it doth 
appeare I doe now hereby declare limit direct and 
appoint that with all convenient speed after my decease 
there shalbe raised satisfied and paid these severall 
summes of money Rents Charges and Annuities herein 
after expressed and likewise all such other summes of 
Money Rents Charges or Annuities which at any time 

214 The Will of Harvey 

hereafter in any Codicill to be hereunto annexed shall 
happen to be limited or expressed And first I appoint 
so much money to be raised and laid out vpon that 
building which I have already begun to erect within 
the Colledge of Physicians in London as will serve to 
finish the same according to the designe already made 
Item I give and bequeath vnto my lo sister in Law 
Mrs Eliab Harvey one hundred pounds to buy some- 
thing to keepe in remembrance of me Item I give 
to my Niece Mary Pratt all that Linnen householdstuffe 
and furniture which I have at Coome neere Croydon 
for the vse of Will Foulkes and to whom his keeping 
shalbe assigned after her death or before me at any 
time Item I give vnto my Niece Mary West and 
her daughter Amy West halfe the Linnen I shall leave 
at London in my chests and Chambers together with 
all my plate excepting my Coffey pot Item I give 
to my lo sister Eliab all the other halfe of my Linnen 
which I shall leave behind me Item I give to my 
lo sister Daniell at Lambeth and to everie one of her 
children severally the summe of fiftie pounds Item 
I give to my lo Coosin Mr Heneage Finch for his 
paines counsell and advice about the contriving of this 
my will one hundred pounds Item I give to all my 
little Godchildren Nieces and Nephews severally to 
everie one Fiftie pounds Item I give and bequeath 
to the towne of Foulkestone where I was borne two 
hundred pounds to be bestowed by the advice of the 
Mayor thereof and my Executor for the best vse of 
the poore Item I give to the poore of Christ 
hospitall in Smithfield thirtie pounds Item I give 
to Will Harvey my godsonne the sonne of my brother 
Mich Harvey deceased one hundred pounds and to 
his brother Michaell Fiftie pounds Item I give to 
my Nephew Tho Cullen and his children one hundred 
pounds and to his brother my godsonne Will Cullen 
one hundred pounds Item I give to my Nephew 
Jhon Harvey the sonne of my lo brother Tho Harvey 

The Will of 1 [arvey 215 

deceased two hundred pounds Item I give to my 
Servant John Raby for his diligence in my and 

sicknesse twentie pounds And to Alice Garth my 
Servant Tenne pounds over and above what I am 
already owing unto her by my bill which was h< t 
mistresses legacie Item I give among the poor 
children of Amy Rigdon daughter of my lo vncle 
Mr Tho Halke twentie pounds Item among other 
my poorest kindred one hundred pounds to be dis- 
tributed at the appointment of my Executor Item I 
give among the servants of my sister I )an at my 
Funeralls Five pounds And likewise among the ser- 
vants of my Nephew Dan Harvey at Coome as much 
Item I give to my Cousin Mary Tomes Fifty pounds 
Item I give to my lo Friend Mr Prestwood one 
hundred pounds Item I give to everie one of my 
lo brother Eliab his sonnes and daughters severally 
Fiftie pounds apiece All which legacies and gifts 
aforesaid are chiefly to buy something to keepe in 
remembrance of me Item I give among the servants 
of my brother Eliab which shalbe dwelling with him 
at the time of my decease tenne pounds Furthermore 
I give and bequeath vnto my Sister Eliabs Sister Mrs 
Coventrey a widowe during her natural life the yearly 
rent or summe of twentie pounds Item I give to 
my Niece Mary West during her naturall life the yearly 
rent or summe of Fortie pounds Item I give for the 
vse and behoofe and better ordering of Will Foulkes 
for and during the term of his life vnto my Niece Mary 
Pratt the yearly rent of tenne pounds which summe if 
it happen my said Niece shall dye before him I desire 
may be paid to them to whome his keeping shalbe 
appointed Item I will that the twentie pounds which 
I yearly allowe him my brother Galen Browne may 
be continued as a legacie from his sister during his 
naturall life Item 1 will that the payments to Mr 
Samuel Fentons children out of the profits of Buckholt 
Lease be orderly performed as my deere deceased lo 

216 The Will of Harvey 

wife gave order so long as that lease shall stand good 
Item I give vnto Alice Garth during her naturall life 
the yearly rent or summe of twentie pounds Item To 
John Raby during his naturall life sixteene pounds 
yearly rent All which yearly rents or summes to be 
paid halfe yearly at the two most vsuall feasts in the 
yeare viz Michaelmas and our Lady day without any 
deduction for or by reason of any manner of taxes 
to be any way hereafter imposed The first payment 
of all the said rents or Annuities respectively to beginne 
at such of those feasts which shall first happen next 
after my decease Thus I give the remainder of my 
lands vnto my lo brother Eliab and his heires All 
my legacies and gifts &c. being performed and dis- 
charged Touching my bookes and householdstuffe 
Pictures and apparell of which I have not already 
disposed I give to the Colledge of Physicians all my 
bookes and papers and my best Persia long Carpet 
and my blue sattin imbroyedyed Cushion one paire of 
brasse Andirons with fireshovell and tongues of brasse 
for the ornament of the meeting roome I have erected 
for that purpose Item I give my velvet gowne to 
my lo friend Mr Doctor Scarbrough desiring him and 
my lo friend Mr Doctor Ent to looke over those 
scattered remnant of my poore Librarie and what 
bookes papers or rare collections they shall thinke fit 
to present to the Colledge and the rest to be Sold 
and with the money buy better And for their paines 
I give to Mr Doctor Ent all the presses and shelves 
he please to make use of and five pounds to buy him 
a ring to keepe or weare in remembrance of me And 
to Dr Scarbrough All my little silver instruments of 
surgerie Item I give all my Chamber furniture tables 
bed bedding hangings which I have at Lambeth to my 
Sister Dan and her daughter Sarah And all that at 
London to my lo Sister Eliab and her daughter or 
my godsonne Eliab as she shall appoint Lastly I 
desire my executor to assigne over the custode of 

The Will of Harvey 217 

Will Fowkes after the death of my Niece Mary Pratt 
if she happen to dye before him vnto the Sister of 
the said William my Niece Mary West Thus I have 
finished my last Will in three pages two of them 
written with own hand and my name subscribed to 
everie one with my hand and seal to the last 

Will Harvey 

Signed sealed and published as the last will and 
testament of me William Harvey In the presence of 
us Edward Dering Henneage Finch Richard Flud 
Francis Finche Item I have since written a Codicill 
with my owne hand in a sheet of paper to be added 
hereto with my name thereto subscribed and my seale. 

Itkm I will that the sumes and charges here specified 
be added and annexed vnto my last will and testament 
published heretofore in the presence of Sir Edward 
Bering and Mr. Henneage Finch and others and as a 
Codicill by my Executor in like manner to be per- 
formed whereby I will and bequeath to John Denn 
sonne of Vincent Denne the summe of thirtie pounds 
Item to my good friend Mr Tho Hobbs to buy some- 
thing to keepe in remembrance of me tenne pounds 
and to Mr Kennersley in like manner twentie pounds 
Item what moneys shalbe due to me from Mr. Hen 
Thompson his fees being discharged I give to my 
friend Mr Prestwood Item what money is of mine 
viz one hundred pounds in the hands of my Cosin 
Rigdon I give halfe thereof to him towards the marriage 
of his niece and the other halfe to be given to Mrs 
Coventrey for her sonne Walter when he shall come of 
yeares and for vse my Cosin Rigdon giving securitie I 
would he should pay none Item what money shalbe 
due to me and Alice Garth my servant on a pawne 
now in the hands of Mr Prestwood I will after my 
decease shall all be given my said servant for her 
diligence about me in my siknesse and service both 
interest and principall Item if in case it so fall out 

218 The Will of Harvey 

that my good friend Mrs Coventrey during her widow- 
hood shall not dyet on freecost with my brother or 
Sister Eliab Harvey Then I will and bequeath to her 
one hundred marke yearly during her widowhood 
Item I will and bequeath to my loving Cosin Mr 
Henneage Finch (more than heretofore) to be for my 
godsonne Will Finche one hundred pounds Item I 
will and bequeath yearly during her life a rent of 
thirtie pounds vnto Mrs Jane Nevison Widdowe in case 
she shall not preferre her selfe in marriage to be paid 
quarterly by even porcons the first to beginn at Christ- 
mas Michaelmas or Lady day or Midsummer which 
first happens after my decease Item I give to my 
Goddaughter Mrs Eliz Glover daughter of my Cosin 
Toomes the yearly rent of tenne pounds from my 
decease vnto the end of five years. Item to her 
brother Mr Rich Toomes thirty pounds as a legacie 
Item I give to John Cullen sonne of Tho Cullen 
deceased all what I have formerly given his father and 
more one hundred pounds Item I will that what 
I have bequeathed to my Niece Mary West be given 
to her husband my Cosin Rob West for his daughter 
Amy West Item what should have bene to my Sister 
Dan deceased I will be given my lo Niece her daughter 
in Law Item I give my Cosin Mrs Mary Ranton 
fortie pounds to buy something to keep in remembrance 
of me Item to my nephews Michaell and Will the 
sonnes of my brother Mich one hundred pounds to 
either of them Item all the furniture of my chamber 
and all the hangings I give to my godsonne Mr Eliab 
Harvey at his marriage and all my red damaske furni- 
ture and plate to my Cosin Mary Harvey Item I give 
my best velvet gowne to Doctor Scarbrowe. 

Will Harvey. 

Memorandum that upon Sunday the twentie eighth 
day of December in the yeare of our Lord one thousand 
sixe hundred fiftie sixe 1 did againe peruse my last will 

The Will of Harvey 219 

which formerly conteined three pages and hath now 
this fourth page .idded to it. And I doe now this 
■nt Sunday December 28 1656 publish and declare 
these foure pages whereof the three last are written with 
my owne hand to be my last will In the presence of 
Henneage Finch John Raby. 

This will with the Codicill annexed was proved at 
London on the second day of May In the yeare of our 
Lord God one Thousand six hundred fiftie nine before 
the Judge for probate of wills and granting Adcons 
lawfully authorised By the oath of Eliab Harvey the 
Brother and sole executor therein named To whom 
Administracon of all and singular the goods Chattells 
and debts of the said deceased was granted and com- 
mitted He being first sworne truely to administer. 1 

Chas. Dyneley 
John Iggulden 
w. f. gostling 


[• The will of Harvey is without date. But was almost certainly made 
some time in the course of 1052. He speaks of certain deeds of declara- 
li. in bearing date the 10th of July, 1651 ; and he provides money for the 
completion of the buildings which he has " already begun to ere^t within 
the Colledge of Physicians." Now these structures were finished in the 
early part of 1653. The will was, therefore, written between July 1651, 
and February 1653. The codicil is also undated: but we may presume 
that it was added shortly before Sunday the 28th of December 1656, the 
day on which Harvey reads over the whole document and lormally 
declares and publishes it as his last will and testament in the presence 
of his friend Henneage Finch, and his faithful servant John Raby.] 




Anastomosis, 63, 127, 1 72 

how far observed by Harvey, 1 2S 

Harvey states his views on, 179, 1S0 

pulsation ot an, 15 

axillary, its bearing on the pulse, 30 

its effect on the pulse, 135 

importance of dissecting the lower, 42 

why its walls thicker than those of'the pulmonary artery, 107 

case in which portion of, ossified, 137 
Argent, Dr. 

dedication of treatise on Heart and Blood to, 5 

referred to, vii, 27 

on the pulse, 30 

on the chick, 34. 

quoted in support of pulsation of heart ot embryo, 46 

circular motion of rain suggested by, compared to that of the 
blood, 56 

on the heart, 93, 97, 105, 166 

his error regarding the mitral valve, 101 

on the study of the lower animals, 137 

on trusting to the senses, 160 

experiments of, 14, 28, 29, 129, 163 

outflow of blood in, 29 


224 Index 


ancient views regarding the, ix 

contain blood only, 12 

contain same blood as the veins, 12 

Galen's experiment on, 12 

filled like bladders, not like bellows, 13 

dilation of, due to impulse of blood, 14 

diastole of, corresponds to systole of heart, 29 

called veins, by Galen, 30, and the ancients, 57 

why empty after death, 62, 140 

coronary, supply the heart itself, 88 

reason for greater thickness of coats of, 106 

nearer to heart, more they differ from veins, 106 

contained only aerial spirits, according to Erasistratus, 140 

ligature of an, of a snake, 66 

experiment of dividing an, 129, 146 

experiment on an exposed uncut, 136 

case of ossification of portion of an, 137 
Arundel, Earl of 

Harvey accompanied the, .on an embassy to the Emperor, 

discovered the lacteals, 117, 1S6 

lacteal vessels of, referred to by Harvey, 197 


Baer, Von 

Harvey, a precursor of, xxi 

on the arm to show flow of blood in the veins, Si et seq. 
Baiihiiz, Caspar 

his observations on the heart, 31 

of Harvey's works, xxiv 

observations on the beat of the heart of a, 33 

observations on the heart of the chick, 34, 36 

Index 225 


its course from veins to arteries, 4- 

in the lower animals, 43 

in the fictus, 44 

its passage through the- longs, 

;. -, passing through the heart, 55 
circular motion of the, 56 

demonstrated from impossibility of whole amount o(, 

being derived from the ingesta, 58 
iunt ejected from ventricle at each beat, 59 
enter- a limb by arteries, leaves it by veins, 67 
circulation of, proved by experiments with ligatures, 67, 68 
quantity of, passing through bloodvessels supports circula- 
tion, 76 
circulation of, supported by valves in the veins. 78 
manner of escape of, in surgical operations, 107 
the whole of the, circulates, 1 14 
is cooled in passing through the lungs, 122 
force with which it flows from an artery, 156 
is of same nature in arteries and veins, 13S, 143 

reasons why a different view has been held, 139, 140 
velocity of, varies in different parts, and at different times, 156 
gives heat to the heart, 167 
passage of, from arteries to veins, \vi, 168 

Casalpinus, Andreas 

claimed in Italy as the discoverer of the Circulation, xi 
this claim criticised, xii 
Calidum nutation, 145 

not distinct from the blood, 146 
Can j lis arteriosus 

of foetus, shrinks gradually after birth, 45 

too minute for Harvey to see, x-w 

first observed by Malpighi, xvi 
Carotid artery 

experiment on the, 129 

force with which blood flows from the. 136 

R lC2 

226 Index 1. 

his interest in Harvey's discovery, xviii 

Harvey appointed physician to, xxii 

remained such by request of the Parliament, xviii 

dedication to, of treatise on Motion of Heart and Blood, 3 

present at a demonstration by Harvey, 153 

first sign of the heart in the, 34 

Aristotle on, 34 

observations of, on the fourth and fifth days of incubation, 30 
Chordte lendineae, 99, 100 

absorbed by the blood, 92 

vessels containing, 1 86 
Circulation of the Blood 

circulation as distinct from motion, xii 

first suggested to Harvey's mind, 50 

compared to circular movement of rain as suggested by 
Aristotle, 56 

confirmed by three propositions, 58 

varies in rapidity, 61 

explains the results of ligatures, 67 ct sea. 

explains phlebotomy, 73 

summary account of, 85, 168 

confirmed by probable reasons, 86 

proved by certain consequences, 90 

confirmed from structure of the heart in many different kinds 
of animals, 96 

doctrine of the, the opposite to that vulgarly entertained, 10S 

first reply to Riolan on the, in 

applies to the whole of the blood, 114 

in the mesentery, 119 

coronary, or a third and very short, 125 

through every part of the body, 126 

second reply to Riolan on the, 133 

reply to those who cry cui lono? 149 

reasons given by opponents for not accepting the, 149. 150 

velocity of, varies with age, sex, temperament, etc., 1 5 > 

influenced by the emotions, 158 

Index 227 

Circulation of the I mlinued) 

i apitulation of work "ii Motion of Heart and Blood, 161 
interference with, followed by dangerous results, 171 

further illustrations of, 170 et scq. 
Columbus, Reatdus 

claimed as discoverer of the Circulation, xi 

referred to in relation to the Pulmonary Circulation, 12, 
16, 50 
Columna cornea 

of the heart, 99 
Co/it • 

of disease spread, explained by circulation, go 

nature of, referred to by Harvey, 193 

the source of all animal motion, 102 

of the fibres of the heart. 105 

of muscles as aid to movement of blood in the veins, 1 16 

means of acquiring, of physical truths discussed, 15S 

vessels supply the heart with blood, 88 

circulation, a third, very short, 125 

vein usually has a valve at its orifice, 125 

Darcy, Sir A'.' 

case of. illustrating obstruction of the circulation through the 
heart, 155 

supports Harvey's discovery, xvii 

Harvey makes his acknowledgments to, 169 

his observations of the heart of a fish, 169 

his explanation of the pulse not accepted by Harvey, 170 
Diastole and Systole 

of arteries as of the heart, 138 

constituting the pulse, 163 

uses of, 112 

failed to reveal any of the "spirits" of the schoolmen, 141 

228 Index 


drinks, their quick action in illustration of the large quantity 
of blood circulating, 49 
Ductus arteriosus 

shrinks gradually after birth. 45 
its function in the fcetus, 9S 


observations on the heart of the, 33 

Harvey a pioneer in the science of, xx 
Ent, Dr. George 

persuaded Harvey to publish his treatise on Generation, xx 
directed in Harvey's will to present his books and collections 

to the College of Physicians, 216 
Harvey left him his presses and shelves, 216 

Harvey's doctrine of, xxi 

thought the arteries contained only spirits or air, 40, 140 


the tides of, the motion of the heart as perplexing as, 22 
Galen refers to, in speaking of the use of the semilunar 

valves, 53 
Riolan applies, to the movement of the blood in the mesenteric 

vessels, 115 

importance of, for scientific observation, 160 


the direct appeal to, viii 

Galen's, to show arteries contain only blood, 12 

Galen's, to show arteries filled like bellows, controverted by 

Harvey, 14 
of arteriotomy, 14, 28, 29 
Galen's, of dividing the trachea. iS 
to observe the beating heart, 24 
of dividing the gill vessels of fishes, 28 
on the hearts of an eel, a fish, and a pigeon, 33 
to show the capacity of the left ventricle, 59 

Index 229 

1 "1 ■ • iment (continued) 

on the heart of .1 snake, 65 

of tying the veins below the heart in serpents ami fishes, 65 

on a man's arm with a bands 

..n the veins of the arm by ligatures, 82, S4 

of tying the vena cava near the lie.irt and dividing car- 
artery, l 

t ialen's, on an artery, 134 
performed and disproved by Harvey, 135 

on an exposed undivided artery, 136 

to show the f arteries and veins the same, 13S 

to show the different character of outflow of blood from 

artery and vein. 147 
to show blood cannot pass from heart by the veins. 147 
with the dried intestine of a dog filled with water to illustrate 

the pulse, 152 
on the jugular vein of a fallow deer, 153 
by appeal to, endeavour to demonstrate circulation, 163 
of dividing exposed artery to observe effect on pulse, 163 
of tying the pulmonary veins, 165 
of bandaging arm and plunging it into cold water, 16S 
of tying the vena portae, 171 
of tying the vena cava near the crural veins. 172 
on the body of a man recently hanged, to show course of 

blood through lungs, 177 

Fabricius, Hieronymus, of Aquapendente 

Harvey's teacher of anatomy at Padua, xiv 

his views on the heart ami lungs, 9 
pulmonary veins, IS 

his anatomical work, 23 

discovered the valves of the veins, 7S 
Finch, Heneage 

Harvey's cousin, advised him as to his will. 214 

witness to codicil of Harvev's will. 217 

experiment on gill vessels of, 28 

observations on the heart of, }} 

230 Index 

Fish (continued) 

the heart of, has only one ventricle, 42 

auricles of the heart of, 103 

Harvey refers to his visits to, 185, 194 
and three of his nephews, 199 

on Harvey's work, viii 
Foramen ovale 

of heart of foetus, 20, 44 

its significance in foetal life. 47, 9S 

Harvey's treatise on the Heart and Blood first published 
there, xv 
Fuliginous vapours 

views of the ancients on, ix, 10, 11, 17 


high regard in which he was held by medievalists, vii 

on the object of the pulse, 9 

his experiment to show arteries contain only blood, 12 

his experiment to prove arteries expand like bellows, and 

controverted by Harvey, 14 
his experiment of dividing the trachea of a dog, 18 
on the beat of the auricles, 32 
quotations from, on movement of the blood, 40, 41 
aware of the use of the semilunar valves, 51, 52 
believed blood passed from right ventricle into the lungs, 53 
on the structure of the heart, 105 
his experiment on an artery, 134 

performed and disproved by Harvey, 135 

at Padua with Harvey, vii, xiv 

as a pioneer in scientific discovery, viii 
Generation of Animals 

Harvey's treatise on, its publication, xx 

interesting points in, xxi 

Harvey refers to his work on the, 177 

Quotation from, on the Acquisition of Knowledge, >:ix 

Index 231 


on Harvey's discovery, xiii 

piuiiccr in scientific discovery, viii 
greatness of his discovery, viii, i\ 

his life, xiii et uq. 

his views on controversy, xviii, 133 

on the manner of acquiring knowledge, xix 

his treatise on Generation, xxi, 177 

his statue, xxii 
I ition in his memory, xxii 

his brother Eliab, xxiii, 212, 219 

his various works, xxiv 

on the pursuit of truth, 7 

vibes how his discovery was received, 23 

his letters, 175 et set/. 

■ n the use of terms, 182 

his will, 2 12 

ideas about the, before the time of Harvey, ix 

object of its beat connected with Respiration by old anato- 
mists, 9 
movements of the, 24 

contracts and becomes paler at its beat, 24, 25 
does not suck in the blood', 27 

the auricles and ventricles of the, their movements, 31 
the auricles of the, the primum vivens, ultimum moriens, 34 
observations on the heart of the chick, 34. 36 
always has auricles or something analogous, 35 
of a shrimp, its movements studied, 36 
movements of, summarised, 37 
intimate connection of lungs and, a grand cause of error to 

the old observers, 39 
of fish, has only one ventricle, 42 
great vessels of the, in the embryo, 44 
foramen ovale of the, in the fcetus, 44, 98, 165 
of embryo, pulsation, etc., known to Aristotle, 45 

232 Index 

Heart (continued) 

compared figuratively to the sun, 57 

amount of blood ejected at each beat of the, 59 

of a live snake, observations on, 65 

influenced by emotions, S7 

curious case of distended heart under emotion, 156 

coronary vessels of, 88 

only organ containing blood for general use, SS 

structure of the, in different classes of animals confirms the 
circulation, 97 

papillary muscles and chordse tendinea? of, 99 

arrangement and use of the valves of the, 100 

the heart a muscle and acts as such, so called by Hippo- 
crates, 104 

development of the, in the foetus, 104 

arrangement of the fibres of, 105 

the first part which exists, 105 

high importance of the, in the bodily economy, 105 

distension of, after hanging, 1 54 

Sir Robert Darcy's case of ruptured, 155 

receives heat from the blood, 167' 

innate heat of, suggested as cause of the pulse, luS 

of the fish, observations of motions of the, 169 

entitled the heart a muscle, 104 

his doctrine as to the constitution of the body, 142 

on the reception of Harvey's discovery, xvii 
Hofmann, Caspar 

letter of Harvey to, 175 
Horst,/. D. 

letters of Harvey to, 195, 197 
Huxley, Prof. T. H. 

on Harvey's treatise on Generation, xxi 

Jugular vein 

Experiment of dividing the, in the fallow deer, to show course 
of the contained blood, 153 

Index 233 

King, The. See Chat Us I. 


discovert i by Aselli, 117, iS6 

Harvey refers to the researches of Aselli and Pecquet on 
the, 186 

Harvey discusses the, in a letter to R. Morison, 1S7, 188 
Lametttiits, And 

quoted by Harvey, 20, 22 
Lennox, Puke of 

Harvey accompanied him abroad, xxii 

of Harvey, 173 ct sea. 


of veins near the heart, 65 

assuming circulation, action and use of ligatures readily under- 
stood, 67, 6S 

of vena cava, 129, 172 

of pulmonary veins, 165 

of vena porta', 171 

absorbed food passes through the, 49 

absorbed chyle passes through the, 92 

in the foetus, 92 

nature of blood brought to, 94 

chyle transferred to, by mesenteric vessels, nS 
I. in: 

speculation on changes in the blood passing through the, 48 

blood cooled on passing through the, 122, 145 

course of blood through the, shown by an experiment on the 
body of a man recently hanged, 177 


the first to observe the capillaries, xvi 
Medical Obserz'a:. 

Harvey refers to his, 157, 158, 171 

234 Index 


externally applied confirm the circulation, 91 

bloodvessels of, 94, 115 

Harvey combats Riolan's denial of circulation in vessels of 
the, 115 

Harvey suggests an experiment to convince him, 171 

valves in the mesenteric veins, 116 

veins of. transfer chyle to the liver, 118 

doctrine of, contrasted with that of Epigenesis, xxi 
Mitral Valve 

references to, 17, 101 

Aristotle's error regarding the, 101 
Morison, A'. 

letter of Harvey to, 1S5 

of the heart, 24, 36 

of the auricles and ventricles, 31 

of the heart summarised, 37 

of the blood from veins to arteries, 42 

of the blood in the fcetus, 44 
lower animals, 43 
is circular, 58 

of the blood in the veins aided by the circumjacent muscles, 

the heart a, and so called by Hippocrates, 104 


Nardi, John, of Florence 

letters cf Harvey to, 184, 193, 199 
Nutrition of the Tissues 

connection of the, with the circulation, 119 


Oration, Harzcian 

founded by Harvey, delivered annually at the College of 
Physicians, xxii 

Index 235 


Harvey and Galileo there together, vii, \iv 

famous for its university. \iv 

Harvey studies medicine at, xiv 

. Thomas 

anatomical examination of the body of, 207 

how best advanced, 112 

Harvey refers to his disc >v ry i the Receptacalum Chyli, 186 

Harvey praises his industry, 196 
Sec also Lacteals 

explained by the circulation. 73 

shows nature of flow of blood in the veins, 154 

influenced by temperature and mental state, 157 
Physicians, College of 

Harvey elected a Fellow of the, xv 

I tarvey built a Convocation Hall for, and gave books to, xvii 
his treatise dedicated to President and Fellows of, 5 

importance of its study, 112 

action of, confirmatory of the circulation, 90 
Pulmonary Artery 

formerly supposed to carry nourishment to lungs, 17 

why coats of, thinner than those of aorta, 107 

transmits far more blood than required for nutrition, 108 
Pulmonary Circulation 

speculation as to its use, 48 

follows from continual passage of blood from right ventricle 
to lungs, and from lungs to left ventricle, 54 

course of, shown in body of a man recently hanged, 177 
Pulmonary Veins 

ancient views regarding their function, 17 

caused by contraction of the ventricle, 29 

due to the impulse or shock of the blood, 30 

236 Index 

Pulse (continued) 

Aristotle on the, 30 

found in all parts of the body, 121 

not inherent in walls of arteries, 135 

in an artery beyond an aneurism, 135 

in an artery beyond an ossified portion, 137 

illustrated by experiment with dried intestine of a dog, 152 

cause of, in arteries near the heart, 163 



how confirmatory ol the circulation, 90 
Riolan,John, fun. 

controversy with Harvey, xix 

quoted on the movements of the heart, 31 

Harvey's First Disquisition addressed to, 109 

presented a copy of his work to Harvey, 1 1 1 

his views on the circulation, 113 

denies the mesenteric circulation, 115 

favoured view that septum of heart is permeable, 123 

Harvey's Second Disquisition to, 131 

Scarborough, Dr. 

a friend to whom Harvey left his surgical instruments, 216 
and his velvet gown, 218 

directed by Harvey's will to present to College of Physicians 
his books and collections, 216 

dependent on pre-existing knowledge ot more obvious 
things, 160 
Semilunar Valves 

references to, 16, 45 

Galen aware of their use, 51 

function to prevent regurgitation, 116, 153 

facts cognisable by, wait on no opinion, 150 

importance of appealing to the, 158, 159 

Aristotle on trusting to the, 160 

Index 237 

Septum of the Heart 

■ • salpinos thought it permeable, xii 

Harvey on the view that it i^ porous, 19, 20 
in believed it porous, 1- i 
Strvetus, Mi 

gave B description of the pulmonary circulation, x 
curious history of his work containing it, xi 

movements of the heart of a, 30 

See Sem 

. ■ us, Jilt e 

discovered the valves of the veins according to Riolan, 7S 
Simon, Sir /. 

on Harvey's discovery, ix 

- ■■. P. m. 

letter of Harvey to, 176 

observations of heart and bloodvessels of a live, 65 
- its 

views of the ancients regarding, ix 

arteries supposed to contain, by Erasistratus, 140 

the common subterfuge of ignorance, 141 

three kinds of, admitted by the medical schools, 141 

not distinct from the blood, 143, 146 

bloodvessels connected with the, 94 

vein of, has a valve, 116 
Systole and Diastole 

of arteries as of heart, 138 

constitute the pulse, 163 

observations on, 170 

Transmission oj Disease 

discussed, 193 
Tricuspid Valve 

referred to, 16, 101, 153 

2 3 8 


Umbilical Vein 

function of, I iS 




semilunar, 16, 45, 116, 153 

tricuspid, 16, 101, 153 

mitral, 17 

Galen on valve of pulmonary artery, 51 

of the veins discovered by Fabricius or Silvius, 78 

of veins, their structure, arrangement, and use of, 7S, 80 

Fabricius did not understand use of valves of veins, 79 

of veins compared with sigmoid valves, 82 

experiments on the arm to show action ot the, and how 
the blood moves in the veins, 82. 84 

not found in all veins, 116 

of the mesenteric veins, 116 

coronary vein has a valve at its orifice, 125 

pulmonary, ancient views regarding their position, 17 

near the heart, experiment, of ligaturing the, 65 

of the arm, experiment on with bandages, 82. S4 

coronary. 88 

of the mesentery, the function of the, 118 

umbilical, function of, 11S 

coronary vein has a valve at its orifice, 125 

experiment on, by cooling the arm, 168 

valves of the. See Valves 
Vena cava 

of snake, experiment upon the, 65 

experiment of tying, near the heart, 129 
Vena porta 

blood passes from the, through the liver, 118 

its branches, 128 

Harvey suggests the experiment of ligaturing it, 171 
I 'en t ride 

no right ventricle if no lung, 15, 54 

the left, the principal part of the heart, 98 

Index 239 

Ventricle (continued) 

the left, three times thicker than the right, 100 

ease of rupture of the, 155 

structure of both, almost identical, 15 

both contract simultaneously, 19 

movements and use of the, 37 

in the foetal heart, 98 

valves of the, 100 

the " Father of Anatomy, 

l'i.>fessor of Anatomy at Padua, xiv 

did not properly understand the heart's motion, 26 

refer* to Galen's experiment on an artery, 135 

ing in his interpretation of Galen's experiment, 138 
VI a 1 • ' n 

letter oi Harvey to, 2CO 



felt in the hand on loosening bandage on the arm, 69 
restored to parts chilled by the influx of blood, 121, 146 

of Harvey drawn up by Heneage Finch, 212, 214 
proved by Eliab Harvey, 219 
legacies by, to Dr-. Scarborough and Ent, 216 

Harvey as forerunner of, xxi 



v^ x 









In Cloth Binding 

In Special Library Binding 

Also Selected Volumes in Leather 



In each section of this list the volumes are arranged, as 
a general rule, alphabetically under the authors' names. 
Where authors appear in more than one section, a reference 
is given, viz.: {See also Fiction). The number at the end 
of each item is the number of the volume in the series. 
Volumes obtainable in Leather are marked l 


Audubon the Naturalist, Life and Adventures of. By R. Buchanan. 601 
Baxter (Richard 1 *, Autobiography of. Edited by Rev. J. M. Lloyd 

Thomas. 868 
Beaconsfleld (Lord), Life of. By J. A. Froude. 666 
Berlioz (Hector), Life of. Translated by Katherine F. Boult. 602 
Blackwell (Dr Elizabeth): Pioneer Work for Women. With an Introduc- 
tion by Mrs Fawcett. 667 
L Boswell's Life of Johnson. 2 vols. 1-2 
(See also Travel) 
Browning (Robert), Life of. By E. Dowden. 701 

Buxton (Sir Thomas Fowell), Memoirs of. Edited by Charles Buxten. 
Introduction by Lord Buxton. 773 [Maurois. 931 

L Byron's Letters. Edited by R. G. Howarth. Introduction by Andre 
Carey (William), Life of: Shoemaker and Missionary. 395 
Carlyle's Letters, and Speeches of Cromwell. 3 vols. 266-8 
„ Reminiscences. 875 

(See also Essays and History) 
l Cellini's (Benvenuto) Autobiography. 51 
Gibber's (Colley) An Apology for his Life. 668 
Constable (John), Memoirs of. By C. R. Leslie, R.A. 563 
Cowper (William), Selected Letters of. Intro, by W. Hadley, M.A. 774 

(See also Poetry and Drama) 
De Quincey's Reminiscences of the Lake Poets. Intro, by E. Rhys. 163 

(See also Essays) 
De Retz (Cardinal): Memoirs. By Himself. 2 vols. 735-6 
Evelyn's Diarv. 2 vols. Introduction by G. W. E. Russell. 220-1 
Forster's Life of Dickens. Intro, by G. K. Chesterton. 2 vols. 781-2 

(See also Fiction) 
Fox (George), Journal of. Text revised by Norman Penney, F.S.A. 

Introduction by Rufus M. Jones, LL.D. 754 
Franklin's (Benjamin) Autobiography. 316 
Fronde's Life of Benjamin Disraeli, Earl of Beaconsfleld. 666 
L Gaskell's (Mrs) Life of Charlotte Bronte. Intro, by May Sinclair. 318 
Gibbon (Edward), Autobiography of. Intro, by Oliphant Smeaton. 511 

(See also History) 
Gladstone, Life of. By G. W. E. Russell ('Onlooker'). 661 
Hastings (Warren), Life of. By Capt. L. J. Trotter. 452 
Helps' (Sir Arthur) Life of Columbus. 332 
Hodson, of Hodson's Horse. By Capt. L. J. Trotter. 401 
Holmes' Life of Mozart. Introduction by Ernest Newman. 564 
Houghton's Life and Letters of Keats. Introduction by Robert Lynd. 801 
Hutchinson (Col.) Memoirs of. Intro. Monograph by F. P. G. Guizot. 317 
Irving's Life of Mahomet. Introduction by Professor E. V. Arnold. 513 
Johnson's Lives of the Poets. Intro, by Mrs Archer-Hind, M.A. 770-1 
Lamb (Charles), Letters of. 2 vols. 342-3 

(See also Essays and For Young People) 
Lewes' Life oi Goethe. Introduction by Havelock Ellis. 269 
Lincoln (Abraham), Life of. By Henry Bryan Binns. 783 

(See also Oratory) 
Lockhart's Life of Robert Burns. Latroduction by E. Rhys. 156 
1, „ Life of Napoleon. 3 

Life of Sir Walter Scott (abridged). 55 
Mazzini, Life of. By Bolton King, M.A. 562 [Newcastle. 722 

Newcastle (First Duke of), Life of, and other writings by the Duchess of 
Outram (Sir J.), The Bayard of India. By Capt. L. J . Trotter. 396 


BIOGRAPHY— continued 

Pepys' Diary. Lord Hr.n hrooke's 1H54 oil. '.' vol*. 33-4 

riutiirih'n Lives of Noble Greeks and Romans. Pryden'a Transintin-] 
Revised, with Introduction, by Arthur Hugh CHonga. 3 rote. 4u; j 

Roosscaa. Confessions of. iYois. > s .''-' 80 

Scott's Lives of the Novelist*. Introduction by I ieorge SalntHbury. 331 
(Set til<,> h"i< -lliiN and Pobtrt) 

8eebohm (Frederic : The Oxford Kofurmow. With a 1'rofaeo by Eogb 
K. Beebobm. 065 

Smiftton's A Life of Bbakespeare, with Criticisms of the Hays. ..1 l 

Southev's Life »f Nelson. .')'.' 

Btriokland's Life of Queen Kllzaboth. 100 

Swift's Journal to Stella. Newly deciphered and edited by J. K. Moor- 
head, [ntrodnotlon by sir Walter Boott 757 
[See also Essays ana Fob fouwa Pboplb) 

\ asarl'a Lives of the Painters. Trans, by A. B. Hinds, 4 vols. -S4-7 

Voltaire's Life of Charles Ml. Introduction by Lt. lion. J. Burns. -.'70 

WsJpole (Horace) Selected Letters of. Intro, by \V. Hadley, M.A. 775 

Wellington, Life of. By <L R. Qlalg. 341 

W -i. -v's Journal. 4 vols. Intro, by Rev. F. W. Macdonald. lo;>-8 

Woounan'8 (Johnl Journal and Other Papora. Introduction by Vlda D. 
Bondder. 403 


.1 - -hvlus' Lyrical Dramas. Translated by Professor J. S. Blackle. 62 
Aristophanes" The Frogs, The Clouds. The Thesmophorlans. 510 

„ The Acharuians, The Knitrhts, and The Birds. Frere's 

Translation. Introduction by John P. Maine. 344 
Aristotle's Politics. Introduction by A. D. Lindsay. 605 

,, Poetics, etc., and Demetrius on Style, etc. Edited bv 

{See also Philosophy) [Itev. T. A. Moxon. 001 

Caesar's The Gallic War and Other Commentaries. Translated by \V. A. 

McDoTitte. 702 
Cicero's Essays and Select Letters. Intro. Note by de Quincey. 345 
L Epii Moral Discourses, eta Klizabeth Carter's Translation. Edited 

by \V. H. D. Rouse. M.A. 404 
Euripides' Plays in 2 vols. Introduction by V. R. Reynolds. Translated 
by Id*. Wodhull and R. Potter, with Shelley's 'Cyclops' and Dean 
Milman's 'Bacchanals.' 63, 2 7 1 
Herodotus. Rawlinaon'a Translation. Edited, with Introduction, by 
E. H. Blakeney, M.A., omittini? Translators' Original Essays, and 
Appendices. 2 vols. 405-6 
l Homer's Iliad. Lord Derby's Translation. 453 

L „ Odyssey. William Cowper's Translation. Introduction by Miss 

F. M. Stawell. 454 

Horace. Complete Poetical Works. 515 [006, and 671 

Hutchinson's (W. M. L.) The Muses' Pageant. Vols. I, IT, and III. 581, 

Livy*a History of Rome. Vols. I-VI. Translated by Rev. Canon Roberts. 

603, 669, 670, 740, 755, and 756 
Lucretius: On the Nature of Things. Translated by W. E. Leonard. 750 
L Marcus Aurelius' Meditations. Introduction by W. H. D. Rouse. 9 
I lato's Dialogues. 2 vols. Introduction by A. D. Lindsay. 456-7 
L „ Republic. Translated, with an Introduction, by A. D. Lindsay. 64 
Plutarch's Moralia. 20 Essays translated by Philemon Holland. 565 
Sophocles' Dramas. Translated by Sir G. Young, Bart. 114 
Thucydides' Peloponneaian War. Crawley's Translation. 455 
L Virgil's .Kneid. Translated by E. Fairfax-Taylor. 161 

„ Eclogues and Georgics. Translated by T. F. Royds, M.A. 222 
Xenophou's Cyropsedia. Translation revised by Miss F. M. Stawell. 67 J 


L Anthologv of Prose. Compiled and Edited by Miss S. L. Edwards. 675 
Arnold's (Matthew) Essays. Introduction by G. K. Chesterton. 115 
„ „ study of Celtic Literature, and other Critical Essays, 

with Supplement by Lord Strangford, etc. 45i 
(See also Poetry) 
l Bacon's Essays. Introduction by Oliphant Smeaton. 10 
(Sec also Philosophy) 
Bagehot's Literary Studies. 2 vols. Intro, by George Sampson. 520-1 
Belloc's (Hilaire) Stories. Kssays, and Foems. 94b 
L Brown's Rab and his Friend, etc. 116 

Burke's Reflections on the French Revolution and contingent Essays. 
Introduction bv A. J. Grieve, M.A. 460 (See also Oratorio 



Canton's (William) The Invisible Playmate, W. V., Her Book, and In 
(See also For Young People) [Memory of W. V. 566 

Carlyle'e Essays. 2 vols. With Notes by J. Russell Lowell. 703-4 
Past and Present. Introduction by R. W. Emerson. 008 
„ Sartor Resartus and Heroes and Hero Worship. 278 
(See also Biography and History) 
Castieli one's The Courtier. Translated by Sir Thomas Hoby. Intro- 
duction by W. H. D. Rouse. 807 
Century of Essays, A. An Anthology of English Essayists. 653 
Chesterfield's (Lord) Letters to his Son. 823 
L Chesterton's (G. K.) Stories, Essays, and Poems. 913 

Coleridge's Biogrraphia Literaria. Introduction by Arthur Symons. 11 
„ Essays and Lectures on Shakespeare, etc. 162 

(See also Poetry) 
l De la Mare's (Walter) Stories, Essays, and Poems 940 

De Quincey's (Thomas) Opium Eater. Intro, by Sir G. Douglas. 223 
„ „ The English Mail Coach and Other Writings. 

Introduction by S. Hill Burton. 609 
(See also Biography) 
Dryden's Dramatic Essays. With an Introduction by W. H. Hudson. 568 
Elyot's Gouernour. Intro, and Glossary by Prof. Foster Watson. 227 
l Emerson's Essays. First and Second Series. 12 
l „ Nature, Conduct of Life, Essays from the 'Dial.' 322 

„ Representative Men. Introduction by E. Rhys. 279 
„ Society and Solitude and Other Essays. 567 
(See also Poetry) 
Florio's Montaigne. Introduction by A. R. Waller, M.A. 3 vols. 440-2 
Froude's Short Studies. Vols. I and II. 13, 705 

(See also History and Biography) 
Gilflllan's Literary Portraits. Intro, by Sir W. Robertson Nicoll. 348 
Goethe's Conversations with Eckermann. Intro, by Havelock Ellis. 

851. (See also Fiction and Poetry) 
Goldsmith's Citizen of the World and The Bee. Intro, by R. Church. 902 

(See also Fiction and Poetry) 
Hamilton's The Federalist. 519 

Hazlitt's Lectures on the English Comic Writers. 411 
„ Shakespeare's Characters. 65 

Spirit of the Asre and Lectures on English Poets. 459 
Table Talk. 321 

Plain Speaker. Introduction by P. P. Howe. 814 
l Holmes' Autocrat of the Breakfast Table. 66 
Poet at the Breakfast Table. 68 
„ Professor at the Breakfast Table. 67 
l Hudson's (W. H.) A Shepherd's Life. Introduction by Ernest Rhys. f?5 

Hunt's (Leifih) Selected Essays. Introduction by J. B. Priestley. S29 
L Huxley's (Aldous) Stories, Essays, and Poems. 935 
Irving's Sketch Book of Geoffrey Crayon. 117 

(See also Biography and History) 
Landor's Imaginary Conversations and Poems: A selection. Edited 
with Introduction by Havelock Ellis. 890 
L Lamb's Essays of Elia. Introduction by Augustine Birrell. 14 
(-See also Biography and For Young People) 
Lowell's (James Russell) Among My Books. 607 

Macaulay's Essays. 2 vols. Introduction by A. J. Grieve, M.A. 225-6 
„ Miscellaneous Essays and The Lays of Ancient Rome. 439 
(See also History and Oratory) 
Machiavelll's Prince. Special Trans, and Intro, by W. K. Marriott. 280 

(See also History) 
Martinengo-Cesaresco (Countess) : Essays in the Study of Folk-Songs. 673 
Mazzini's Duties of Man, etc. Introduction by Thomas Jones, M.A. 224 
Milton's Areopagitica, etc. Introduction by Professor C. E. Yaughan. 795 
(See also Poetry) 
L Mitford's Our Village. Edited, with Introduction, by Sir John Squire. 927 
Montagu's (Lady) Letters. Introduction by R. Brimley Johnson. 69 
Newman's On the Scope and Nature of University Education, and a 
paper on Christianity and Scientific Investigation. Introduction by 
(See also Philosophy) [Wilfred Ward. 7 23 

Osborne's (Dorothy) Letters to Sir William Temple. Edited and con- 
notated by Judge Parry. 674 
Penn's The Peace of Europe. Some Fruits of Solitude, etc. 724 
Prelude to Poetry, The. Edited by Ernest Rhys. 789 
laynold's Discourses. Introduction by L. March Phiiiipps. 11a 



l Rhys's New Book of Boom and Nonsense. 813 

Rousseau's Kmlle. Translated t>y Barbara l oxley. 5is 
(See alao Philosophy and Thjcoli 

L Ruflklu's Crown of Wild olive and Oestns of Ak'lala. 3-3 
„ Elements of Drawing and PerspeotlTe. 217 

Ethics of tbe Dost. Introduction by Grace Rhys. 282 

„ Modern l'ii!iit<T-<. 5 vols, Introduction by Lionel Oast. 20<< ia 
„ Prs-Raphaelltlsm. Leotnns on Architecture and Painting, 
Academy Notes, 1855-9, and Notew on th» Turner Gallery. 
Introduction by Lanrenoe Blnyon. 218 
l „ Besameand Lilies, The Two Paths, and The Kins; of the Golden 

Liver. Introdnotlon by sir OUrer Lodge, 819 
„ Seven Lamp* of Architecture. Intro, by Bolwyn Image, 207 
St onrt> of Venice. 3 vols. Intro, by L. March Phlllipps. 213-15 
Tlmo and Tide with otb'T K-ivH. 450 
Unto Thla Last. The political Economy of Art. 216 
(See aUo Fob Young I'koplb) 
Spectator, The. 4 vols. Introdnotlon hy G. G reg or y Smith. 164-7 
Spencer's (Herbert i Essays on Education. Intro, by O. 97, Eliot. 504 
Sterne's BentlmentsJ Journey and Journal and Letters to Eliza. Ii 

'•'> Fiction) I by George Saintsbury. 790 

L Stevenson's In the South Seas and Island Nights' Entertainments. 7<iy 

L ,, Virglnibus Puerisque and Familiar Studies of Men and 

(See alto Fiction, Poetry, and Travel) [Books. 765 

Swift's Tale of r. Tub, The Battle of the Books, etc. 347 


Swinncrton's (Frank) The Georgian Literary Scene. 943 

Table Talk. Edited by J. C. Thornton. 906 

Taylor's (Isaac) Words and Places, or Etymologica ' Illustrations of 
History. Ethnology, and Geography. Intro, by Edward Thomas. 5) 7 

Thackeray's (W. M.> 'i'ho English Humourists and The Four Georges. 
Introduction by Walter Jerrold. 610 (See also Fiction) 

i. Thoreau's Walden. Introduction by Walter Raymond. 281 

Trench's On the Study of Words and English Past and Present. Intro- 
duction by George Sampson. 788 

Tytler's Essav on the Principles of Translation. 103 

Walton's Compleat Angler. Introduction by Andrew Lang. 70 


ALmard's The Indian Scout. 428 
i iinsworth'a (Harrison) Old St. Paul's. Intro, by W. E. A. Axon. 522 

The Admirable Crichton. Intro, by E. Kh)8. 804 
, „ The Tower of London. 400 

Windsor Castle. 709 

Rookwood. Intro, by Frank Swinnerton. 870 
American Short Stories of the Nineteenth Century. Edited by John 
Couxnoe. 840 
L Austen's (Jane) Emma. Introduction by R. B. Johnson. 24 

„ Mansfield Park. Introduction by U. B. Johnson. 23 
, „ Nort banger Abbey and Persuasion. Introduction bv 

R. B. Johnson. 25 
L ,, Pride and Prejudice. Introduction by R. B. Johnson. 22 

„ Sense and Sensibility. Intro, by R. B. Johnson. 21 
Balzac's (Uonore de) Atheist's Mass. Preface by George Saintsbury. 229 
„ Catherine de Medici. Introduction by Geortre 
Saintsbury. 419 * 

Chri6t in Flanders. Introduction by Georze 
Saintsbury. 284 b 

„ „ Cousin Pons. Intro, by George Saintsbury. 463 

„ „ Eugenie Grandet. Intro, by George Saintsbury. 169 

M „ Lost Illusions. Intro, by George Saintsbury. 6.36 

L „ OldGoriot,. Introduction by George Saintsbury. 170 

„ The Cat and Racket, and Other Stories. 349 
„ The Chouans. Intro, by George Saintsburr. 285 
„ The Country Doctor. Intro. George Saintsbury. 530 

The Countrv Parson. 686 
„ The Quest of the Absolute. Introduction by Georga 
Saintsbury. 2S6 
„ „ The Rise and Fall of Cesar Birotteau. 596 

1 he Wild Ass's Skin. Intro, by George Saintsbury. 26 
„ ., L isule Mirouet. Intro, by George Saintsbury. 733 


FICTION— continued 

Barbusse'a Under Fire. Translated by Fitzwater Wray. 798 
L Bennett's (Arnold) The Old Wives' Tale. 919 
L Blackmore'8 (R. D.) Lorna Doone. 304 

L Borrow's Lavengro. Introdnction by Thomas Seccombe. 119 
l „ Romanv Rye. 120 (See also Travel) 

L Bronte's (Anne) The Tenant of Wildfell Hall and Apnea Grey. 685 
h „ (Charlotte) Jane Eyre. Introdnction by May Sinclair. 287 

L „ „ Shirley. Introduction by May Sinclair. 288 

„ „ The Professor. Introduction by May Sinclair. 417 

L „ ,, Villette. Introduction by May Sinclair. 351 

L „ (Emily) Wuthering Heights. 243 

Bumey's (Fanny) Evelina. Introduction by R. B. Johnson. 352 
Butler's (Samuel) Erewhon and Erowhon Revisited. Introduction by 
Desmond MacCarthy. 881 
The Way of All Flesh. Introduction by A.J. Hopp6. 895 
Collins' (Wilkie) The Woman in White. 464 
L Conrad's Lord Jim. Introduction by R. B. Cunninghame Graham. 925 
L Converse's (Florence) Long Will. 328 

Dana's (Richard H.) Two Years before the Mast. 588 
Daudet's Tartarin of Tarascon and Tartarin of the Alps. 423 
Defoe's Fortunes and Misfortunes of Moll Flanders. Intro, by G. A. Aitken. 
„ Captain Singleton. Introduction by Edward Garnett. 74 [837 
„ Journal of the Plague Year. Introduction by G. A. Aitken. 289 
„ Memoirs of a Cavalier. Introduction by G. A. Aitken. 283 
(See also For Young People) 
Charles Dickens' Works. Each volume with an Introduction by G. K. 

L American Notes. 290 i. Little Dorrit. 293 

L Barnaby Rudge. 76 L Martin Chuzzlewit. 241 

L Bleak House. 236 L Nicholas Nickleby. 238 

L Child's History of England. 291 L Old Curiosity Shop. 173 
L Christmas Books. 239 L Oliver Twist. 233 

L Christmas Stories. 414 L Our Mutual Friend. 294 

L David Copperficld. 242 L Pickwick Papers. 235 

L Dombey and Son. 240 Reprinted Pieces. 744 

Edwin Drood. 725 Sketches by Boz. 237 

l Great Expectations. 234 l Tale of Two Cities. 102 

Hard Times. 292 L Uncommercial Traveller. 53 3 

Disraeli's Coningsby. Introduction by Langdon Davies. 535 
Dostoevtsky's (Fyodor) Crime and Punishment. Introduction by 

Laurence Irving. 501 
Letters from the Underworld and Other Tales 

Translated by C. J. Hogarth. 654 
Poor Folk and The Gambler. Translated by C. J 

Hogarth. 711 
The Possessed. Introduction by J. Middleton 
Murry. 2 vols. 861-2 [533 

Prison Life in Siberia. Intro. by Madame Stepniak. 
The Brothers Karamazov. Translated by Con- 
stance Garnett. 2 vols. 802-3 
The Idiot. 682 
Du Manner's (George) Trilby. Introduction by Sir Gerald du Maurier 

With the original illustrations. 863 
Dumas' Black Tulip. Introduction by Ernest Rhys. 174 
Chicot the Jester. 421 

Le Chevalier de Maison Rouge. Intro, by Julius Bramont. 614 
„ Marguerite de Valois ('La Reine Margot'). 326 
l „ The Count of Monte Cristo. 2 vols. 393-4 

The Forty-Five. 420 
L „ The Three Musketeers. 81 

„ The Vicomte de Bragelonne. 3 vols. 593-5 
L „ Twenty Years After. Introduction by Ernest Rhvs. 175 

Edgar's Cressy and Poictiers. Introduction by Ernest Rhys. 17 
„ Runnymede and Lincoln Fair. Intro, by L. K. Hughes 320 
(.S'ee also For Young Peopt.k) 
Edgeworth's Castle Rackrent and The Absentee. 410 
L Eliot's (George) Adam Bede. 27 
Felix Holt. 353 
„ „ Middlemarch. 2 vols. 854-5 

L „ „ Mill on the Floss. Intro. Sir W. Robertson Nicoll. 325 

l „ „ Romola Introduction by Rudolf Dircks. 231 

l „ ., Scenes of Clerical Life. 468 


FICTION— continued 

Fllot'a (George* Silnx Marner. Introduction by Annie Matliixion. 121 
l English Short Stories. An Anthology- T43 

Erokm&nn-Cbatrl&n'a Tho Conaorlpl and Waterloo. 3.M 

The Story of a Pendant. Translated by C. J. 
Hogarth. 2 vols. 706-7 
Fenlmoro Cooper's The Ivi-ralaver. 77 

The Last of the Mohicans. 79 

The Pathfinder. 78 
The Pioneers. 171 

The Prairie. 17-' 
Ferrier'a (Susan) Marriage. Introduction by IT. L. Morrow. Kid 
Fielding's Amelia. Intro, by «'.eorg» Salntsbury. 8 Tola. B59 3 

Jonathan Wild, and The Journal of a Voyage to Lisbon. 
Introduction by George Saintsbury. 877 
„ Joeepb Andrews. Introduction by Oeorgo Salntsbury. 467 

Tom Jones. Intro, by George Salntahury. 2 vols. 355-6 
Flaubert's Madamo Bovary. Translated by Eleanor Marx-Aveling. 
Introduction by George Salntebury. 808 

.iMinbO. Translated bv J. S. Chartrcs. Introduction bv 
Pro feasor F. C. Green. 869 
French Short Stories of the 19th and 20th Centuries. Selected, with 
an Introduction by Professor F. C. Green. 896 
L Galsworthy's (John) The Country House. 917 

Gait's Annals of a Parish. Introduction by Halllie Mncdonald. 427 
Gaak&Q'a (Mn) Cousin Phillls, etc. Intro, by Thos. Seccombe. 615 
L ,. Cranford. 83 

Mary Barton. Introduction by Thomas Soccomba. 593 
North and South. 680 

Svlvia's Lovers. Intro, by Mrs Ellis Chadwick. 524 
Gleig'a (G. R.) The Subaltern. 708 
Goethe's Wilhelm Meister. Carlyle's Translation. 2 vols. 599-600 

(See also Essays and Poetry) 
Gogol's (Nicol) Dead Souls. Translated by C. J. Hogarth. 726 
Taras Bulba and Other Tales. 740 
L Goldsmith's Vicar of Wakefield. Introduction by J. M. D. 295 
(See also Essays and Poetry) 
Goncharov's Oblomov. Translated bv Natalie Duddington. 878 
Gorki's Through Russia. Translated by C. J. Hogarth. 741 
Harte's (Bret) Luck of Roaring Camp and other Tales. 681 
Hawthorne's The House of the Seven Gables. Intro, by Ernest Rhys 176 
L „ The Scarlet Letter. 122 

„ The Blithedale Romance. 592 

The Marble Faun. Intro, by Sir Leslie Stephen. 424 
I, Twee Told Tales. 531 

{/See also For Young People) 
l Hugo's (Victor) Les Miserables. Intro, by S. R. John. 2 vols. 363-4 
L „ .. Notre Dame. Introduction by A. O. Swinburne. 422 

„ Toilers of the Sea. Introduction bv Ernest Rhys 509 
Italian Short Stories. Edited by D. Pettoello. 876 
James's (G. P. R.) Richelieu. Introduction by Rudolf Dircks. 357 
L James's I Henry) The Turn of the Screw and The Aspern Papers. 912 

Kingsley's (Charles) Alton Locke. 462 
L „ » Hereward the Wake. Intro, by Ernest Rhys. 296 

L „ .. Hypatia. 230 

. ,, Westward Hoi Introduction by A. G. Grieve. 20 

" .. Yeast. 611 

(See also Poetry and For Young People) 
(Henry) Geoffrey Hamlyn. 416 
„ „ Ravenshoe. 28 

L Lawrence's (D. H.) The White Peacock. 914 

Lever's Harry Lorrequer. Introduction by Lewis Melville. 177 
l Loti's (Pierre) Iceland Fisherman. Translated by W. P. Bainea. 92J 
L Lover's Handy Andy. Introduction by Ernest Rhvs. 178 
L Lytton's Harold. Introduction by Ernest Rhys. 15 
L „ Last Days of Pompeii. 80 

„ Last of the Barons. Introduction by R. G. Watkin. 18 
„ Rienzi. Introduction by E. H. Blakeney, M.A. 532 
(See also Travel) 
MacDonald's tGeorge) Sir Gibbie. 678 

(See also Romance) ((Mrs Hinkson). 324 

Manning's Mary Powell and Deborah's Diary. Intro, by Katherine Tynan 
„ Sir Thomas More. Introduction by Ernest Rhys. 19 


FICTION — continued 

Marryat's Jnonb Faithful. 618 
L „ Mr Midshipman Easy. Introduction by R. B. Johnson. 82 

„ Percival Keene. Introduction by R. Brimley Johnson. 358 

„ Peter Simple Introduction by R. Brimley Johnson. 232 
The King's Own. 580 
(See also For Young People) 
l Maugham's (Somerset) Cakes and Ale. 932 

Maupassant's Short Stories. Translated by Marjorie Laurie. Intro- 
duction by Gerald Gould. 907 
Melville's (Herman) Moby Dick. Introduction by Ernest Rhys. 179 
„ „ Omoo. Introduction by Ernest Rhys. 297 

„ ., Typee. Introduction by Ernest Rhys. 180 

L Meredith's (George) The Ordeal of Richard Feverel. 916 

Merimee's Carmen, with Provost's Manon Lescaut. Introduction by 

Philip Henderson. 834 
Mickiewicz's (Adam) Pan Tadeusz. 842 
L Moore's (George) Esther Waters. 933 

Mulock's John Halifax, Gentleman. Introduction by J. Shaylor. 123 

Neale's (J. M.) The Fall of Constaninople. 655 

Paltock's (Robert) Peter Wilkins; or, The Flying Indians. Introduction 

by A. n. Bullen. 676 
Pater's Marius the Epicurean. Introduction by Osbert Bnrdett. 903 
Peacock's Headlong Hall and Nightmare Abbey. 327 
L Poe's Tales of Mystery and Imagination. Intro, by Padraic Colum. 336 
(See also Poetry) 
Prevost's Manon Lescaut, with M6rhnee's Carmen. Incroduction by 
Philip Henderson. 834 
L Priestlev's Angel Pavement. 938 

Pushkin's (Alexander) The Captain's Daughter and Other Tales. Trans. 

by Natalie Duddington. 898 
Quiller-Couch's (Sir Arthur) Hetty Wesley. 864 [2 vols. 865-6 

Radcliffe's (Ann) Mysteries of Udolpho. Intro, by R. Austin Freeman. 
L Reade's (C.) The Cloister and the Hearth. Intro, by A. C. Swinburne. 29 
Reade's (C.) Peg Woffington and Christie Johnstone. 299 
Richardson's (Samuel) Pamela. Intro, by G. Saintsbury. 2 vols. 683-4 
Clarissa. Intro, by Prof. W. L. Phelps. 4 vols. 
" 882—5 

Russian Authors, Short Stories from. Trans, by R. S. Townsend. 758 
Sand's (George) The Devil's Pool and Francois the Waif. 534 
Scheffel's Ekkehard: a Tale of the Tenth Century. 529 
Scott's (Michael) Tom Cringle's Log. 710 
Sir Walter Scott's Works: 

Abbot The 124 i- Ivanhoe. Intro, by Ernest Rhys. 18 

Anne of Geierstein. 125 l Kenil worth. 135 

l Antiquary, The. 126 L Monastery, The. 136 

P.lack Dwarf and Legend of Old Mortality. 137 

Montrose. 128 Peveril of the Peak. 133 

Bride of Lammermoor. 129 Pirate, The. 139 

Castle Dangerous and The Sur- Quentin Durward. 140 

geon's Daughter. 130 L Redgauntlet. 141 

Count Robert of Paris. 131 L Rob Roy. 142 

i Fair Maid of Perth. 132 St. Ronan's Well. 143 

Fortunes of Nigel. 71 Talisman, The. 144 

i Guy Mannering. 133 L \\ averley. 75 

l Heart of Midlothian, The. 134 l Woodstock. Intro, by Edward 
Hiehland Widow and Betrothed. 127 Garnett. 72 

(See also Biography and Poetry) 
Shchedrin's The Golovlyov Family. Translated by Natalie Duddington. 

Introduction by Edward Garnett. 908 
Shelley's (Mary Wollstonecraft) Frankenstein. 616 
Sheppard's Charles Auchester. Intro, by Jessie M. Middleton. 505 
Sienkiewicz (Henryk). Tales from. Edited by Monica M. Gardner. 871 
Shorter Novels, Vol. I. Elizabethan and Jacobean. Edited by Philip 
Henderson. 824 
Vol. II. Jacobean and Restoration. Edited by Philip 

Henderson. 841 
Vol. III. Eighteenth Century (Beckford's Vathek, 
Wal pole's Castle of Otranto, and Dr. Johnson's 
Pmollett's Peregrine Pickle. 2 vols. 838-9 [Rasselas). 856 

Roderick Random. Introduction by H. W. Hodges. 790 
Stendhal's Scarlet and Black. Translated by C. K. Seoti Moncrieff. 
2 vols. 945-6 


FICTION— continued 

l Stern**! Tristram Shandy. Introduction by George Saintsburr. 617 

(/Bee iiU,, h.v,AVS) 
L BteVSnSOn'l IT Jekvll ami Mr Hyde. The Merrv Men, ami Other '! 
L .. The Master at Ballantrae and The Ml usk Arrow. 764 1767 

l ,, raw [aland an i Kidnapped 

Bt p.m. [ntroduotlon by Ernest Rhys. 904 
{/Bee alto Essays, Postbt, and Tbavi 
Burteea' tarrocks' j»m.n and Jollities. 817 
L Tales of Detection. I - ductlon, byDorothyL. 8ayere, 998 

Thaokei ■ e and the Ring and other Walter Jerrold. 

•nd. Introduction by Walter Jerrold. 73 [35D 

Newooxnes. Introduction by Walter Jerrol L I rols. 4G5— 6 
Pendennls. Intro, by Walter Jerrold. 2 vols. 496—6 
Roondabont Papera. 687 

Vanity Fair, [ntrodnotion by Hon. Wblt^law Raid. 298 
Virginians, [ntrodnotion by Walter Jerrold. I vols. 507-8 

>>•'■■ E AYS) 

L Tolstoy's Anna BZarenlna. Trans, by lioohelle 9. Townsend. 2 toN, rtl 2—13 
Childhood, Boyhood, and Youth. Trans, by i . J. Hogarth. 691 
Master and Man, and other Parables and Tales. 469 
War and Peace. 3 vols. 625-7 
Trollope'a ^Anthony) Harchoeter Towera. 30 
Dr. Thome. 360 

Framley Parsonage. Intro, by Ernest Rbys. 181 
n .. The i > olden Lion of Granpere. Introduction by 

Sir Hugh W'sJpole. 761 
Tbe Last Chronicle of Barcet. 2 vols. 391-3 
Phineas Finn. Intro, by Sir Hugh Walpole. 3 vols. 
The Small House at Ailington. 361 1832-3 

„ „ Tbe Warden. Introduction by Ernest Rhvs. 182 

Tuxgcnev'a Fathers and Sons. Translated by C. J. Hogarth. 742 
Liza. Translated by W. R, S. Ralston. 67 7 
Virgin Soil. Translated bv Rochelle S. Townsend. 528 
l Voltaire's Candida and Other Tales. 936 
l. Walpole'a (Hu?hl Mr Pcrrin and Mr Traill. 918 

L Wells's (H. G.) The Time Maehine and The Wheels of Chance. 915 
W byte-MelflUe'B The Gladiators. Introduction by J. Mavrogordato. 623 
Woods i.Mrs Henry) The Cbanninga. 84 

Woolf's (Virginia) To the Lighthouse. Intro, by D. M. Hoare. 949 
Yonge'a (Charlotte M.) The Dove in the Eagle's Nest. 329 

„ The Heir of Redclyflo. Intro. Mrs Meynell. 362 

(See also Fob Young People) 
Zola's (Emilo) Germinal. Tauslatcd by Havelock Ellis. 897 


Anglo-Saxon Chronicle, The. Translated by James Ingram. 624 
Mede's Ecclesiastical History, etc. Introduction by Vida D. Scudder. 479 
Burnet's History of His Own Times. 85 
L Carlyle's French Revolution. Introduction by H. Belloc. 2 vols. 31-2 

(See also Biography and Essayh) 
L Creasy's Decisive Battles of the World. Introduction by E .Rhys. COO 
De Joinville (See Villehardouin) 

ininiy's (Jean Victor) A History of France. 2 vols. 737-8 
Finlay's Byzantine Empire. 33 

„ Greece under the Romans. 185 

Froude's Henry VIII. Intro, by LlewellTn Williams. M.P. 3 vols. 372-4 

Edward VI. Intro, by Llewellyn Williams, M. P.. B.C.L. 375 

Mary Tudor. Intro, by Llewellyn Williams, M.P., B.C.L. 477 

History of Qneen Elizabeth's Reign. 5 vols. Completing 

Froude's 'History of England,' in Pi vols. 583-7 
(See also Essays and Biography) 
Gibbon's Decline and Fall of the Roman Empire. Edited, with Introduc- 
tion and Notes, by Oliphant Smeaton, M.A. 6 vols. 434-6, 474-6 
(See also Biography | 
Green's Short History of the English People. Edited and Revised by 
L. Cecil Jane, with an Appendix by R. P. Farley, B.A. 2 vols. 727-8 
G rote's History of Greece. Intro, by A. D. Lindsay. 12 vols. 186-97 
Hallam'8 (Henry) Constitutional History of England. 3 vols. 621-3 
Holinshed's Chronicle as used in Shakespeare's Plays. Introduction by 

Professor Allardyce Nicoll. 800 
lrving's (Washington) Conquest of Granada. 478 

(See also Essays and Biography) 


HISTORY— continued 

Josephus' Wars of the Jews. Introduction by Dr Jacob Hart. 712 
l Macaulay's History of England. 3 vols. 34-6 
(See also Essays and Oratory) 
Maine's (Sir Henry) Ancient Law. 734 

Merivale's History of Rome. (An Introductory vol. to Gibbon.) 433 
Mignet's (F. A. M.) The French Revolution. 713 
Milnian's History of the Jews. 2 vols. 377-8 
Mommsen's History of Rome. Translated by W. P. Dickson, LL.D. 

With a review of the work by E. A. Freeman. 4 vols. 542-5 
L Motley's Dutch Republic. 3 vols. 86-8 

Parkman's Conspiracy of Pontiac. 2 vols. 302-3 

Paston Letters, The. Based on edition of Knight. Introduction by 

Mrs Archer-Hind, M.A. 2 vols. 752-3 
Pilgrim Fathers, The. Introduction by John Masefleld. 480 
h Pinnow's History of Germany. Translated by M. R. Brailsford. 929 
Political Liberty, The Growth of. A Source-Book of English History. 

Arranged by Ernest Rhys. 745 [M.A. 2 vols. 397-8 

Prescott's Conquest of Mexico. With Introduction by Thomas Seccombe, 

„ Conquest of Peru. Intro, by Thomas Seccombe, M.A. 301 

Sismondi's Italian Republics. 250 

Stanley's Lectures on the Eastern Church. Intro, by A. J. Grieve. 251 
Tacitus. Vol. I. Annals. Introduction by E. H. Blakeney. 273 

,, Vol. II. Agricola and Germanla. Intro, by E. H. Blakeney. 274 
Thierry's Norman Conquest. Intro, by J. A. Price, B.A. 2 vols. 198-9 
Villehardouin and. De Joinville's Chronicles of the Crusades. Translated, 

with Introduction, by Sir F. Marzials, C.B. 333 
Voltaire's Age of Louis XIV. Translated by Martyn P. Pollack. 780 


L Anthology of British Historical Speeches and Orations. Compiled by 
Ernest Rhys. 714 
Bright's (John) Speeches. Selected with Intro, by Joseph Sturge. 252 
Burke's American Speeches and Letters. 340 (See also Essays) 
Demosthenes: Select Orations. 546 
Fox (Charles James): Speeches (French Revolutionary War Period). 

Edited with Introduction by Irene Cooper Willis, M.A. 759 
Lincoln's Speeches, etc. Intro, by the Rt. Hon. James Bryce. 206 

(See also Biography) 
Macaulay's Speeches on Politics and Literature. 399 

(See also Essays and History) 
Pitt's Orations on the War with France. 145 


L A Kempis' Imitation of Christ. 484 

Ancient Hebrew Literature. Being the Old Testament and Apocrypha. 

Arranged by the Rev. R. B. Taylor. 4 vols. 253-6 
Aristotle, The Nicomachean Ethics of. Translated by D. P. Chase. 

Introduction by Professor J. A. Smith. 547 
(See also Classical) 
Bacon's The Advancement of Learning. 719 (See also Essays) 
Berkeley's (Bishop) Principles of Human Knowledge, New Theory of 

Vision. With Introduction by A. D. Lindsay. 483 
Boehme's (Jacob) The Signature of All Things, with Other Writings. 

Introduction by Clifford Bax. 569 
Browne's Religio Medici, etc. Introduction by Professor C. H. Herford. 92 
Bunyan's Grace Abounding and Mr Badman. Introduction by G. B. 

Harrison. 815 (See also Romance) 

Burton's (Robert) Anatomy of Melancholy. Introduction by Holbrook 

Jackson. 3 vols. 886-8 
Butler's Analogy of Religion. Introduction by Rev. Ronald Bayne. 90 
Descartes' (Rene) A Discourse on Method. Translated by Professor John 

Veitch. Introduction by A. D. Lindsay. 570 
L Ellis' (Havelock) Selected Essays. Introduction by J. S. Collis. 930 
L Gore's (Charles) The Philosophy of the Good Life. 924 

Hindu Scriptures. Edited by Dr. Nicol Macnicol. Introduction by 

Rabindranath Tagore. 944 
Hobbes' Leviathan. Edited, with Intro, by A. D. Lindsay, M.A. 691 
Hooker's Ecclesiastical Polity. Intro, by Rev. H. Bayne. 2 vols. 201-2 
Hume's Treatise of Human Nature, and other Philosophical Works. 

Introduction by A. D. Lindsay, M.A. 2 vols. 548-9 
James (William): Selected Papers on Philosophy. 739 



Kant's Critique of Pure Reason. Tran-lat<vl l.v J. M. H MlLlelohn 

Introduction by A. D. 1 . . M. \ 

K,!1, rhe Christian Year. Introduction bv J. c. Shalrp. «90 
Kins Edward \ l Flrrt and Second Prayer Books. Introduction by the 

Right Kev. Klshnp of Gloucester. 448 
L Koran, The. Rod well's Translation. 380 

Latimer's Sermorw. [ntrodnctlon by Uimn Pcechln? 40 

Law's Berlona Call to n Permit and Hoiv i.if.-. yi 

Leibniz^ Philosophical Writing*. Selected and trana by Mary Morris 

Introduction by O. R. Morris, M.A. DOS 
Lock , e .' 8 .. Two Tri,a,1 »f" "f Olrll Government. Introduction by Professor 

\\ llliam B. Carponter. 7.'>1 
Malthus on the Principles of Population. I i ila 899 ■ 
Mill's (J. '•iSttmrn I tOltarlanlran, Liberty, Rei .rivo Government 

With Introduction by A. D. Lindsay. M.A. 4 - 2 
.. Subjection of Women. (See Wollstonccraff Marr, vwier SOTJOfOE ) 
U pe B L topia. Introduction bv Judge O'llairan. I<U 
L New Testament. Arranged in the order in whl ib tbo books came to the 
Christians of the First Century, 93 
Newman's Apologia pro Vita Sua. Intro, by Dr Charles Saroloa 630 

(See also Essays) 
Nietzsche's Thus Spake Zarathnstra. Translated by A. Tille and 

>i. m. Bosnian. 
PalneV Rights nf Man. Introduction by G. J. Ilolvoake 718 
P**^ B a \S?"*«*' .Translated by W. F. Trotter. Introduction by 
r. S. Eliot. 874 [CI E 403 

Ramayana and the Mahabharata. The. Translated by Romesh Dutt 
Renan's Life of Jesus. Introduction by Right Kev. Chas. Gore, D D 805 
Robertson's (KW) Sermons on Religion and Life, Christian Doctrine, 
and Bible Subject*. Each Volume with Introduction by Canon 
Burnett. 3 vols. 37-9 
Robinson's (Wade) Tbo Philosophy of Atonement and Other Sermons 

Introduction by Rev. F. B. Meyer. 637 
Rousseau's (J. J.) The Social Contract, etc. 660 (See also Essays) 
St Augustine's Confessions. Dr I'usey's Translation. 200 
t. St Francis: The Little Flowers, and The Life of St Francis. 4 85 
Seeley's Ecce Homo. Introduction bv Sir Oliver Lodge 305 
Spinoza's Ethics, etc. Translated by Andrew J. Boylo. With Intro- 
duction by Professor Santayana. 4*1 
Swedenborg's (Emmanuel) Heaven and HelL 379 

The Divine Love and Wisdom. 635 
„ The Divine Providence. 658 

L .. ., The True Christian Religion. 893 


Anglo-Saxon Poetry. Edited bv Professor R. K. Gordon. 791 
Arnold's (Matthew) Poems, 1840-66, Including Thvrsis. 334 
Ballads, A Book of British. Selected by R. 13. Johnson. 572 
Beaumont and Fletcher, The Select Plavs of. Introduction bv Professor 

Baker, of Harvard University. 506 
BHTcson's Plays. Vol. I. The Newly Married Couple. Leonardo, A 
Gauntlet. Trans, by R. Farquharson Sharp 625 
„ .. Vol. II. The Editor, The Bankrupt, and The King 

Translated by R. Farquharson Sharp. 6'J6 
Blake's Poems and Prophecies. Introduction by Max Plowman 792 
l Browning's Poems, 1833-44. Introduction by Arthur Wan rh 41 
L Browning's Poems, 1844-64. 42 

The Ring and the Book. Intro, by Chn,s. W. nodell. 502 
L Burns' Poems and Songs. Introduction bv J. Douglas, y 1 
Byron's Poetical and Dramatic Works. 3" vols. 486-8 
Caldcron: Six Plays, translated by Edward FitzGerald. 819 
L Chaucer's Canterbury Tales. Edited by Principal Bun-ell, M A 307 
Coleridge, Golden Book of. Edited by Stopford A. Brooke 43 

(See also Essays) 
Cowper (William). Poems of. Edited by H. I'Anson Fausset. 872 
(See also Biography) 
l Dante's Divine Comedy (Gary's Translation). Specially edited bv 
Edmund Gardner. 308 
Donne's Poems. Edited by H. I'Anson Fausset. 867 
Dryden's Poems. Edited by Bonamy Dobrec. 910 
Eighteenth-Century Plays. Edited by John Hampden. 818 


POETRY AND DRAMA— continued 

Emerson's Poems. Introduction by Professor Bakewell, Yalo, U.S.A.. 715 
L English Religious Verse. Edited by Q. Lacey May. 937 

Everyman and other Interludes, including eight Miracle Plays. Edited 

by Ernest Rhys. 381 

L FitzGerald'e (Edward) Omar Khayyam and Six Plays of Calderon. 819 

L Goethe's Faust. Parts I and II. Trans, and Intro, by A. G. Latham. 335 

(See also Essays and Fiction) [well. 921 

L Golden Book of Modern English Poetry, The. Edited by Thomas Cald- 

Goldcn Treasury of Longer Poems, The. Edited by Ernest Rhys. 746 

Goldsmith's Poems and Plays. Introduction by Austin Dobson. 415 

(-See also Essays and Fiction) 
Gray's Poems and Letters. Introduction by John Drinkwater. 628 
Hebbel'e Plays. Translated with an Introduction by Dr O. K. Allen. 601 
Heine: Prose and Poetry. 911 

Herbert's Temple. Introduction by Edward Thomas. 309 
Herrick's Hesperides and Noble Numbers. Intro, by Ernest Rhys. 310 
L Ibsen's Brand. Translated by F. E. Garrett. 716 
L „ Ghosts, The Warriors at Helgeland, and An Enemy of the People. 

Translated by R. Farquharson Sharp. 552 
L „ Lady Inger of Ostraat, Love's Comedy, and The League of 
Youth. Translated by R. Farquharson Sharp. 729 
„ Peer Gvnt. Translated by R. Farquharson Sharp. 747 

l „ A Doll's House, The Wild Duck, and The Lady from the Sea. 
Translated by R. Farquharson Sharp. 491 
„ The Pretenders, Pillars of Society, and Ro nioreholm. Translated 
by R. Farquharson Sharp. 659 
Jonson's (Ben) Plays. Introduction by Professor Sohelling. 2 vols. 489-90 
Kalidasa: Shakuntala. Translated by Professor A. W. Ryder. 629 
L Keats' Poems. 101 

Kingsley's (Charles) Poems. Introduction by Ernest Rhys. 793 
(See alio Fiction and For Younq People) 
L Langland's (William) Piers Plowman. 571 

Lessing's LaocoOn, Minna von Barnhelm, and Nathan the Wise. 813 
L Longfellow's Poems. Introduction by Katherine Tynan. 382 

Marlowe's Plays and Poems. Introduction by Edward Thomas. 383 
l Milton's Poems. Introduction by W. H. D. Rouse. 384 
(.See also Essays) 
Minor Elizabethan Drama. Vol. I. Tragedy. Selected, with Introduction, 
by Professor Thorndike. Vol. II. Comedy. 491-2 
L Minor Poets of the 18th Centurv. Edited by H. I' Anson Fausset. 844 

Minor Poets of the 17th Century. Edited by R. G. Howarth. 873 
L Modern Plavs. 942 

Molieie's Comedies. Introduction by Prof. F. C. Green. 2 vols. 830-1 
L New Golden Treasury, The. Au Anthology of Songs and Lyrics. 695 

Old Yellow Book, The. Introduction by Charles E. Hodell. 503 
L Omar Khayyam (The Rubaiyat of). Trans, by Edward Fit/Gerald. 819 
L Palgrave's Golden Treasury. Introduction by Edward Hutton. 96 
Percy's Reliques of Ancient English Poetry. 2 vols. 148-9 
Poe's (Edgar Allan) Poems and Essays. Intro, by Andrew Lang. 791 

(-See also Fiction) 
Pope (Alexander): Collected Poems. Introduction by Ernest Rhys. 760 
Procter's (Adelaide A.) Legends and Lyrics. 150 

Restoration Plays, A Volume of. Introduction by Edmund Gosse. 604 
L Rossetti's Poems and Translations. Introduction by E. G. Gardner. 627 
Scott's Poems and Plays. Intro, by Andrew Lang. 2 vols. 550-1 
(»Se^ also Biography and Fiction) 
l Shakespeare's Comedies. 153 

L „ Historical Plays, Poems, and Sonnets. 151 

L „ Tragedies. 155 

L Shelley's Poetical Works. Introduction by A. H. Koszul. 2 vols. 257-3 
L Sheridan's Plays. 95 

Spenser's Faerie Queene. Intro, by Prof. J. W. Hales. 2 vols. 443— t 
„ Shepherd's Calendar aud Other Poems. Edited by Philip 
Henderson. 879 
Stevenson's Poerns-A Child's Garden of Verses, Underwoods, Songs of 
Travel, Ballads. 768 (See also Essays, Fiction, and Travel) 
L Tchekhov. Plays and Stories. 91 1 

Tennyson's Poems. Vol. I, 1S30-50. Introduction by Ernest Rhys. 44 
Vol. IL 1857-70. 626 [Harrison. 899 

Twenty One-Act Plays. Selected by John Hampden. 947 
Webster and Ford. Plays. Selected, with Introduction, by Dr. G. B. 
Whitman's (Wait) Leaves of Grass (I), Democratic Vistas, etc. 573 


America. I>i. 


Asia. Do. 


Africa and Australia. 


POETRY AND DRAMA— continued 

Wilde i Oscar). Plajl, Pro,.- Writings and P. ..inn. 858 

l Wordsworth's Shorter Poems. Introdacti m i>y Eraett Rhys. 203 
Longer Poems. Note by Editor. J>l 


Atlas of Ancient and Classical Geojrraphy. Many coloured and line 

Maps; Historical Gazetteer, Index, etc. 451 
Iliofmiphlful Dictionary of English Literature. 449 

s-aphical lMetlonary of Foreign Literature. 'juO 
Dates. Dictionary of. 66 I 

Dictionary of Quotation* and Proverbs. 2 vols. 809-10 
Everyman*! Eiiglish Dictionary. 770 

Literary uud Historical Atlas. I. Europe. Many coloured and line Maps; 

full Index and Gazetteer. 496 


1\'. Africa and Australia. Do. 662 
Kon-Classica] Mythology, Dictionary of. 632 
Reader's ijuide to Everyman's Library, by R. Farquharsou Sharp. 
Introduction by Ernest Rhys. 889 

Roget's Thesauru- ox English Words ami Phrases. 2 vols. 630-1 
Smith's Smaller Classical Dictionary. Revised and Edited by E. H. 

Blakcney. M.A. 495 
Wright's An Encyclopaedia of Gardening. 555 


Aueassln and Nlcolette, with other Medieval Romances. 4 97 
Boccaccio's Decameron. (Unabridged.) Translated by J. M. Rigg. 
Introdnction by Edward Hutton. 2 vols. 845-6 
L Bnnyan's Pilerlm's Progress. Introduction by Rev. H. K. Lewis. 204 

Burnt Njal, The Story of. Translated by Sir George Dasent. 558 
l Cervantes' Don Quixote. Motteux's Translation. Lockhart's Intro- 
;ion. 8 vols. 385-6 
Chretien de Troyes: Eric and Enid. Translated, with Introduction and 

Notes, by William Wistar Comfort. 698 
French Medieval Romances. Translated by Eugene Mason. 557 
■ iTrey of Monmouth's Histories of the Kings of Britain. 577 
Qrettlr Saga, The. Newly Translated by G. Ainslie Bight. 609 
Gudrun. Done Into English by Margaret Armour. 880 
Guest's (Lady; Mabinogion. Introduction by Rev. R. Williams. 97 
Heimskringla: The Olaf Sagas. Translated by Samuel Laing. Intro- 
duction and Notes by John Beveridge. 717 
„ Sagas of the Norse Kings. Translated by Samuel Laing. 

Introduction and Notes by John Beverldge. 847 
Holy Graal, The High History of the. 445 

Kalevsla. Introduction by W. F. Kirby, F.L.S., F.E.S. 2 vols. 259-60 
Le Sage's The Ad\tntur* of Gil Bias. Intro, by Anatole Le Bras. 2 vols. 
MacDonald's (George) Phantastes: A Faerio Romance. 732 [437-8 

(See also Fiction) 
Malory's Le Morte d'Arthur. Intro, by Professor Rhys. 2 vols. 45-6 
L Morris (William): Early Romances. Introduction by Alfred Noyoa. 261 
„ ,, The Life and Death of Jason. 575 

Morte d'Arthur Romances, Two. Introduction by Lucy A. Paton. 634 
Nibelungb, The Fall of the. Translated by Margaret Armour. 312 
Rabelais' '1' he Heroic Deeds of Gargantua and PantagrneL Introduction 

by D. B. Wyndham Lewis. 2 vols. 826-7 
W ace's Arthurian Romance. Translated by Eugene Mason. Laya- 
mon's Brut. Lntroduction by Lucy A. Patou. 678 


Bovle's The Sceptical Chymist. 559 

Darwin's The Origin of Species. Introduction by Sir Arthur Keith. Sll 

(See also Travel) [E. F. Bozraan. 922 

L Eddington's (Sir Arthur) The Nature of the Physical World. Intro, by 

Euclid: the Elements of. Todhunter's Edition. Introduction by Sir 

Thomas Heath, K.C.B. 891 
Faraday's (Michael) Experimental Researches in Electricity. 576 
Galton'e Inquiries into Human Faculty. Revised by Author. 263 
George's (Henry) Progress and Poverty. 560 
Hahnemann's (Samuel) The Organon of the Rational Art of Healing. 

Introduction by C. E. Wheeler. 6t>3 



SCIENCE— continued 

Harvey's Circulation of the Blood. Introduction by Ernest Parkyn. 262 
Howard's State of the Prisons. Introduction by Kenneth Ruck. 835 
Huxley's Essays. Introduction by Sir Oliver Lodge. 47 

„ Select Lectures and Lay Sermons. Intro. Sir Oliver Lodge. 498 
Lvell's Antiquity of Man. With an Introduction by R. H. Rastall. 700 
Marx's (Karl) Capital. Translated by Eden and Cedar Paul. Intro- 
duction by G. D. H. Cole. 2 vols. 848-9 
Miller's Old Red Sandstone. 103 

Owen's (Robert) A New View of Society, etc. Intro, by G. D. H. Cole. 799 
L Pearson's (Karl) The Grammar of Science. 939 

Ricardo's Principles of Political Economy and Taxation. 590 
Smith's (Adam) The Wealth of Nations. 2 vols. 412-13 
Tyndall's Glaciers of the Alps and Mountaineering in 1861. 
White's Selborne. Introduction by Principal Windle. 48 
Wollstonecraft (Mary), The Rights of Woman, with John Stuart Mill's 
The Subjection of Women. 825 


A Book of the ' Bounty. * Edited by George Mackaness. 950 

Anson's Voyages. Introduction by John Masefield. 510 

Bates' Naturalist on the Amazon. With Illustrations. 446 

Belt's The Naturalist in Nicaragua. Intro, by Anthony Belt, F.L.S. 561 

Burrow's (George) The Gypsies in Spain. Intro, by Edward Thomas. 697 

L ' The Bible in Spain. Intro, by Edward Thomas. 151 

" Wild Wales. Intro, by Theodore Watts-Dunton. 49 
(See also Fiction) 
Boswell's Tour in the Hebrides with Dr Johnson. 387 

(See also Biography) 
Burton's (Sir Richard) First Footsteps in East Africa. 500 
Cobbett's Rural Rides. Introduction by Edward Thomas. 2 vols. 63S-9 

L Cook's Voyages of Discovery. 99 

Crevecceur's (H. St John) Letters from an American Farmer. 640 
Darwin's Voyage of the Beagle. 104 

(See also Science) . 

Defoe's Tour Through England and Wales. Introduction by G. D. H. 
(See also Fiction) [Cole. 820-1 

Dennis' Cities and Cemeteries of Etruria. 2 vols. 183-4 
Dufferin's (Lord) Letters from High Latitudes. 499 
Ford's Gatherings from Spain. Introduction by Thomas Okey. 152 
Franklin's Journey to the Polar Sea. Intro, by Capt. R. F. Scott. 447 
«iraldus Cambrensis: Itinerary and Description of Wales. 272 
Hakluvt's Voyages. 8 vols. 264, 265, 313, 314, 338, 339. 388, 389 
Kinglake's Eothen. Introduction by Harold Spender, M.A. 337 
Lane's Modern Egyptians. With many Illustrations. 315 
MandevUle's (Sir John) Travels. Introduction by Jules Bramont. 812 
Park (Muneo): Travels. Introduction by Ernest Rhys. 205 
Peaks, Pastes, and Glaciers. Selected by E. H. Blakeney, M.A. 778 

l Polo's (Marco) Travels. Introduction by John Masefield. oOb 

Roberts' The Western Avernus. Latro. by Cunninghame Graham. 762 

L Speke's Discovery of the Source of the Nile. 50 

L Stevenson's An Inland Voyage, Travels with a Donkey, and Silverado 

Squatters. 706 

(Sec also Essays, Fiction, and Poetry) 
Stow's Survey of London. Lntroduction by H. B. Wheatley. 589 
Wakefield's Letter from Sydney and Other Writings on Colonization. 828 
Waterton's Wanderings in South America. Intro by E feelous 772 
Young's Travels in France and Italy. Intro, by Thomas Okey. 720 


L JEsop's and Other Fables: An Anthology from all sources. 657 
Alpotfs Little Men. Lutroduction by Grace Rhys. 512 
Alcott s £^ue Women and Good wives. Intro, by Grace Rhys. 243 
Andersen's Fairy Tales. Illustrated by the Brothers Robinson. 4 
Andersen s **£* Fairy Tales illustrated by Mary Shillabeer. 822 

Annals of Fairyland. The Reign of King Oberon. 365 
^^ The Reign of King Cole. 366 

Asgard and the"Norse Heroes. Translated by Mrs Boult. 689 
Baker's Cast up by the Sea. 53 9 
L baUantyne's Coral Island. 245 

Martin Rattler. 246 

Ungava. Datroduction by Ernest Rhys. 27b 


FOR YOUNG PEOPLE— continue! 

I Browne's (Frances) Granny's Wonderful <'h:iir. Introduction by Dollle 
R/irlf..r.i- 112 
Bulnuct/s (Thomas) The .\ k 'o of Fable, 179 

„ ,, Legends of Charlemagne. Intro. by Krnest ithys. 6i<i 

L Canton's A Child'! B<">k of Saints. by T. H. Robinson. 61 

(See also Essays) 
i ' trroD'a Alios in Wonderland, Through the Looklng-Gla illus- 

trated tiv t hf Author. Introduction by ECrneel Rhys. 836 
i from i hanoer. 537 
I Dodl'B Pinoochio; or. The 8tory of a Puppet. '>33 
l OonTerse'e [Florence] The Boose <>f Prayer. (See alei I'ktion) 

Cox'i sir •;. w.> Tales of Ancient Greece. 7 •_' l 
Defoe's Kobinson Crusoe. Illustrated by J. A. Symington. 59 
[See also Fiction) 
Ige'e (Mary Manes) Hans Hrlnker: or, The Silvor Skates. 020 
Edgar's Heroes of England. 471 
(See also Fiction) 
l Ewing's (Mrs) Jackanapes. Daddy Darwin's Dovecot. Illustrated by 
It. Caldeoott, and The story of a Short Life. 731 
Mrs Overtheway's Remembrances. 730 
L Fairy Cold. Illustrated by Herbert Cole. 157 
L Fairy Tales from the Arabian Nights. Illustrated. 249 
Froissart's Chronicles. 57 

Gatty's Parables from Nature. Introduction by Grace Rhys. 153 
Grimm's Pairy Tales. Illustrated by R. Anning Boll. 56 
Hawthorne's wonder Book and Tanglewood Talcs. 5 

(See also Fiction) 
Howard's Rattlin the Reefer. Introduction by Guy Pocoek. 857 
L Hughes' Tom Brown's School Days. Illustrated by T. Robinson. 53 
Ingelow*8 (Jean) Mopsa the Fairy. Illustrated by Dora Curtis. 619 
Jeneries'a i Richard) Bevis, the Story of a Boy. Introduction by Guy 
Pocoek. 850 
L Kingsley's Heroes. Introduction by Grace Rhys. 113 

Madam How and Lady Why. Introduction by C. I. Gardiner, 
L „ Water Babies and Glaucus. 277 [M.A. 777 

Kingston's Peter the Whaler. 
Three Midshipmen. 7 
l Lamb's Tales from Shakespeare. Illustrated bv A. Rackham. i 

(See also Biography and Essays) 
l Lear (and others): A Book of Nonsense. 806 
Marryat's Children of the New Forest. 247 

Little Savage. Introduction by R. Brimley Johnson. 159 
Mastennan Ready. Introduction bv R. Brimley Johnson. 160 
Settlers in Canada. Introduction by R. Brimley Johnson. 370 

(Edited by) Rattlin the Reefer. 857 
(See also Fiction) 
Martineau's Feats on the Fjords, etc. Illustrated bv A. Rackham. 429 
Mother Goose's Nursery Rhymes. Illustrated. 473 
Poetry Book for Boys and Girls. Edited by Guy Pocoek. 894 
Reid's (Mayne) The Boy Hunters of the Mississippi. 582 

The Boy Slaves. Introduction by Guv Pocoek. 797 
Ruskin's The Two Boyhoods and Other Passages. 688 
(See also Essays) 
l Sewell's (Anna) Black Beauty. Illustrated by Lucy Kemp-Welch. 743 
L Spyri's (Johanna) Heidi. Illustrations bv Lizxio Lawson. 131 
L Story Book for Boys and Girls. Edited by Guv Pocoek. 9Ji 

Stowe'e Uncle Tom's Cabin. 371 
L Swift's Gulliver's Travels. Illustrated by A. Rackham. 60 

(See also Biography and Essays) 
L Swiss Family Robinson. Illustrations by Chas. Folkard. 430 
Verne's (Jules) Abandoned. 50 BJustrations. 368 

>• .. Dropped from the Clouds. 50 Illustrations. 367 

L „ „ Five Weeks in a Balloon and Around the World in Eighty 

Days. Translated by Arthur Chambers and P. Desages. 
L •• ,. Twenty Thousand Leagues Under the Sea. 319 [77J 

.. ., The Secret of the Island. 50 illustrations. 309 

Yonge's (Charlotte M.) The Book of Golden Deeds. 330 

•» » The Lances of Lynwood. Illustrated by Dora 

Curtis. 57 9 
fc ■> .. The Little Duke. Illustrated by Dora Curtis. 470 

(Set also Fiction) 













Hade in Great Britain at The Temple Press, Letchworth, Herts (M 241) 

HAKVLY, William. 

An anatomical disquisition 101 
on the motion of the heart. ..43